diff --git a/dibi/dibi.php b/dibi/dibi.php
index f7593d3a..2477374b 100644
--- a/dibi/dibi.php
+++ b/dibi/dibi.php
@@ -14,7 +14,7 @@
  * @author     David Grudl
  * @copyright  Copyright (c) 2005, 2007 David Grudl
  * @license    http://php7.org/dibi/license  (dibi license)
- * @version    0.9a (Revision: $WCREV$, Date: $WCDATE$)
+ * @version    0.9b (Revision: $WCREV$, Date: $WCDATE$)
  * @category   Database
  * @package    Dibi
  * @link       http://php7.org/dibi/
@@ -24,13 +24,10 @@
 /**
  * Check PHP configuration
  */
-if (version_compare(PHP_VERSION , '5.0.3', '<')) {
-    throw new Exception('dibi needs PHP 5.0.3 or newer');
+if (version_compare(PHP_VERSION , '5.1.0', '<')) {
+    throw new Exception('dibi needs PHP 5.1.0 or newer');
 }
 
-if (preg_match('#on$|true$|yes$|[+-]?0*[1-9]#iA', ini_get('zend.ze1_compatibility_mode'))) {
-    throw new Exception('dibi cannot run with zend.ze1_compatibility_mode enabled');
-}
 
 
 
@@ -91,7 +88,7 @@ class dibi
         FIELD_COUNTER =    'c', // counter or autoincrement, is integer
 
         // dibi version
-        VERSION =          '0.9a (Revision: $WCREV$, Date: $WCDATE$)';
+        VERSION =          '0.9b (Revision: $WCREV$, Date: $WCDATE$)';
 
 
     /**
@@ -400,11 +397,12 @@ class dibi
      *
      * @param callback
      * @return void
+     * @throws InvalidArgumentException
      */
     public static function addHandler($callback)
     {
         if (!is_callable($callback)) {
-            throw new DibiException("Invalid callback");
+            throw new InvalidArgumentException("Invalid callback");
         }
 
         self::$handlers[] = $callback;
diff --git a/dibi/drivers/untested/mssql.php b/dibi/drivers/mssql.php
similarity index 92%
rename from dibi/drivers/untested/mssql.php
rename to dibi/drivers/mssql.php
index 068d8bea..1fc1cd1d 100644
--- a/dibi/drivers/untested/mssql.php
+++ b/dibi/drivers/mssql.php
@@ -99,7 +99,7 @@ class DibiMsSqlDriver extends DibiDriver
 
     public function insertId()
     {
-        throw new DibiException(__METHOD__ . ' is not implemented');
+        throw new BadMethodCallException(__METHOD__ . ' is not implemented');
     }
 
 
@@ -157,7 +157,7 @@ class DibiMsSqlDriver extends DibiDriver
 
     public function getMetaData()
     {
-        throw new DibiException(__METHOD__ . ' is not implemented');
+        throw new BadMethodCallException(__METHOD__ . ' is not implemented');
     }
 
 
@@ -173,7 +173,7 @@ class DibiMsSqlDriver extends DibiDriver
         }
 
         if ($offset) {
-            throw new DibiException('Offset is not implemented');
+            throw new InvalidArgumentException('Offset is not implemented');
         }
     }
 
diff --git a/dibi/drivers/mysql.php b/dibi/drivers/mysql.php
index bbe20d60..a1ae88be 100644
--- a/dibi/drivers/mysql.php
+++ b/dibi/drivers/mysql.php
@@ -115,8 +115,8 @@ class DibiMySqlDriver extends DibiDriver
         $connection = $this->getConnection();
         $res = @mysql_query($sql, $connection);
 
-        if ($res === FALSE) {
-            throw new DibiDatabaseException(mysql_error($connection), mysql_errno($connection), $sql);
+        if ($errno = mysql_errno($connection)) {
+            throw new DibiDatabaseException(mysql_error($connection), $errno, $sql);
         }
 
         return is_resource($res) ? new DibiMySqlResult($res) : TRUE;
@@ -194,7 +194,7 @@ class DibiMySqlDriver extends DibiDriver
 
     public function getMetaData()
     {
-        throw new DibiException(__METHOD__ . ' is not implemented');
+        throw new BadMethodCallException(__METHOD__ . ' is not implemented');
     }
 
 
diff --git a/dibi/drivers/mysqli.php b/dibi/drivers/mysqli.php
index 3fd66e03..67446593 100644
--- a/dibi/drivers/mysqli.php
+++ b/dibi/drivers/mysqli.php
@@ -89,8 +89,8 @@ class DibiMySqliDriver extends DibiDriver
         $connection = $this->getConnection();
         $res = @mysqli_query($connection, $sql);
 
-        if ($res === FALSE) {
-            throw new DibiDatabaseException(mysqli_error($connection), mysqli_errno($connection), $sql);
+        if ($errno = mysqli_errno($connection)) {
+            throw new DibiDatabaseException(mysqli_error($connection), $errno, $sql);
         }
 
         return is_object($res) ? new DibiMySqliResult($res) : TRUE;
@@ -179,7 +179,7 @@ class DibiMySqliDriver extends DibiDriver
 
     public function getMetaData()
     {
-        throw new DibiException(__METHOD__ . ' is not implemented');
+        throw new BadMethodCallException(__METHOD__ . ' is not implemented');
     }
 
 
diff --git a/dibi/drivers/odbc.php b/dibi/drivers/odbc.php
index d10e0457..1cd4be84 100644
--- a/dibi/drivers/odbc.php
+++ b/dibi/drivers/odbc.php
@@ -122,7 +122,7 @@ class DibiOdbcDriver extends DibiDriver
 
     public function insertId()
     {
-        throw new DibiException(__METHOD__ . ' is not implemented');
+        throw new BadMethodCallException(__METHOD__ . ' is not implemented');
     }
 
 
@@ -192,7 +192,7 @@ class DibiOdbcDriver extends DibiDriver
 
     public function getMetaData()
     {
-        throw new DibiException(__METHOD__ . ' is not implemented');
+        throw new BadMethodCallException(__METHOD__ . ' is not implemented');
     }
 
 
@@ -207,7 +207,7 @@ class DibiOdbcDriver extends DibiDriver
            $sql = 'SELECT TOP ' . (int) $limit . ' * FROM (' . $sql . ')';
         }
 
-        if ($offset) throw new DibiException('Offset is not implemented in driver odbc');
+        if ($offset) throw new InvalidArgumentException('Offset is not implemented in driver odbc');
     }
 
 
diff --git a/dibi/drivers/untested/oracle.php b/dibi/drivers/oracle.php
similarity index 88%
rename from dibi/drivers/untested/oracle.php
rename to dibi/drivers/oracle.php
index b0cbca49..127fdfd4 100644
--- a/dibi/drivers/untested/oracle.php
+++ b/dibi/drivers/oracle.php
@@ -80,8 +80,8 @@ class DibiOracleDriver extends DibiDriver
         $statement = oci_parse($connection, $sql);
         if ($statement) {
             $res = oci_execute($statement, $this->autocommit ? OCI_COMMIT_ON_SUCCESS : OCI_DEFAULT);
-            if (!$res) {
-                $err = oci_error($statement);
+            $err = oci_error($statement);
+            if ($err) {
                 throw new DibiDatabaseException($err['message'], $err['code'], $sql);
             }
         } else {
@@ -97,14 +97,14 @@ class DibiOracleDriver extends DibiDriver
 
     public function affectedRows()
     {
-        throw new DibiException(__METHOD__ . ' is not implemented');
+        throw new BadMethodCallException(__METHOD__ . ' is not implemented');
     }
 
 
 
     public function insertId()
     {
-        throw new DibiException(__METHOD__ . ' is not implemented');
+        throw new BadMethodCallException(__METHOD__ . ' is not implemented');
     }
 
 
@@ -167,7 +167,7 @@ class DibiOracleDriver extends DibiDriver
 
     public function getMetaData()
     {
-        throw new DibiException(__METHOD__ . ' is not implemented');
+        throw new BadMethodCallException(__METHOD__ . ' is not implemented');
     }
 
 
@@ -210,7 +210,7 @@ class DibiOracleResult extends DibiResult
 
     public function seek($row)
     {
-        //throw new DibiException(__METHOD__ . ' is not implemented');
+        //throw new BadMethodCallException(__METHOD__ . ' is not implemented');
     }
 
 
diff --git a/dibi/drivers/untested/pdo.php b/dibi/drivers/pdo.php
similarity index 88%
rename from dibi/drivers/untested/pdo.php
rename to dibi/drivers/pdo.php
index df583626..2a1b9f33 100644
--- a/dibi/drivers/untested/pdo.php
+++ b/dibi/drivers/pdo.php
@@ -76,7 +76,7 @@ class DibiPdoDriver extends DibiDriver
 
     public function affectedRows()
     {
-        throw new DibiException(__METHOD__ . ' is not implemented');
+        throw new BadMethodCallException(__METHOD__ . ' is not implemented');
     }
 
 
@@ -127,7 +127,7 @@ class DibiPdoDriver extends DibiDriver
     public function escape($value, $appendQuotes = TRUE)
     {
         if (!$appendQuotes) {
-            throw new DibiException('Escaping without qoutes is not supported by PDO');
+            throw new BadMethodCallException('Escaping without qoutes is not supported by PDO');
         }
         return $this->getConnection()->quote($value);
     }
@@ -144,7 +144,7 @@ class DibiPdoDriver extends DibiDriver
 
     public function getMetaData()
     {
-        throw new DibiException(__METHOD__ . ' is not implemented');
+        throw new BadMethodCallException(__METHOD__ . ' is not implemented');
     }
 
 
@@ -154,7 +154,7 @@ class DibiPdoDriver extends DibiDriver
      */
     public function applyLimit(&$sql, $limit, $offset = 0)
     {
-        throw new DibiException(__METHOD__ . ' is not implemented');
+        throw new BadMethodCallException(__METHOD__ . ' is not implemented');
     }
 
 } // class DibiPdoDriver
diff --git a/dibi/drivers/postgre.php b/dibi/drivers/postgre.php
index b11d0721..b6463111 100644
--- a/dibi/drivers/postgre.php
+++ b/dibi/drivers/postgre.php
@@ -191,7 +191,7 @@ class DibiPostgreDriver extends DibiDriver
 
     public function getMetaData()
     {
-        throw new DibiException(__METHOD__ . ' is not implemented');
+        throw new BadMethodCallException(__METHOD__ . ' is not implemented');
     }
 
 
diff --git a/dibi/drivers/sqlite.php b/dibi/drivers/sqlite.php
index 144dfc4e..37646b22 100644
--- a/dibi/drivers/sqlite.php
+++ b/dibi/drivers/sqlite.php
@@ -79,9 +79,8 @@ class DibiSqliteDriver extends DibiDriver
         $connection = $this->getConnection();
         $res = @sqlite_query($connection, $sql, SQLITE_ASSOC);
 
-        if ($res === FALSE) {
-            $code = sqlite_last_error($connection);
-            throw new DibiDatabaseException(sqlite_error_string($code), $code, $sql);
+        if ($errno = sqlite_last_error($connection)) {
+            throw new DibiDatabaseException(sqlite_error_string($errno), $errno, $sql);
         }
 
         return is_resource($res) ? new DibiSqliteResult($res) : TRUE;
@@ -158,7 +157,7 @@ class DibiSqliteDriver extends DibiDriver
 
     public function getMetaData()
     {
-        throw new DibiException(__METHOD__ . ' is not implemented');
+        throw new BadMethodCallException(__METHOD__ . ' is not implemented');
     }
 
 
diff --git a/dibi/libs/resultset.php b/dibi/libs/resultset.php
index aa23e2ae..312644d3 100644
--- a/dibi/libs/resultset.php
+++ b/dibi/libs/resultset.php
@@ -21,16 +21,6 @@
 
 
 
-// PHP < 5.1 compatibility
-if (!interface_exists('Countable', FALSE)) {
-    interface Countable
-    {
-        function count();
-    }
-}
-
-
-
 /**
  * dibi result-set abstract class
  *
diff --git a/readme.txt b/readme.txt
index f723df10..8dc1bb63 100644
--- a/readme.txt
+++ b/readme.txt
@@ -10,7 +10,7 @@ Thank you for downloading Dibi!
 Database access functions in PHP are not standardised. This is class library
 to hide the differences between the different databases access.
 
-The files in this archive are released under the NEW BSD license.
+The files in this archive are released under the Dibi license.
 See license.txt in this directory for a copy of the license.
 
 
diff --git a/version.txt b/version.txt
index 86c8749f..7b8fa205 100644
--- a/version.txt
+++ b/version.txt
@@ -1,4 +1,4 @@
-Dibi version 0.9a
+Dibi version 0.9b
 
 Revision: $WCREV$
 Date: $WCDATE$