Invalid library (maybe not a PHP library) : Error during pdo db driver load

Hello,

On Loading my new PDO-interface based driver, PHP gives the error:

"PHP: Startup: Invalid library (maybe not a PHP library) 'php_pdo_mydb.dll
in unknow on line 0 "

I wrote a PDO-based driver, modelling the code on lines of  SQLite driver.
Compiled my driver as win32-dll , added the extension to php.ini. on running
PHP, I get the above error  .

To crosscheck, I used DependencyWalker tool to see if I have missed some
Dll, I find that tools seems to find my Dll fine.
The output list of Dll pdependancies of my driver-Dll looks exactly like
that of php_pdo_sqlite.dll

I have generated my dll using VC9.0 on windows-vista, with following
preprocessor flags:

WIN32;ZEND_DEBUG=0;_USE_32BIT_TIME_T;PHP_WIN32;ZEND_WIN32;_DEBUG;_WINDOWS;_USRDLL;PDO_GROOVY_EXPORTS;

Please let me know, where could be the potential problem.

thanks,
-sanjeev kumar
Please let me know, where could be the potential problem.

thanks,
-sanjeev kumar