mariadb 5.5.36 with innodb plugin

I installed mariadb 5.5.36 on a win32 system. Everything runs fine except innodb requests are 2 x slower than an identical MySQL installation. So I want to switch back to original innodb plugin to test the performance with it. In my.ini I put under [mysqld] the following: ignore_builtin_innodb plugin-load=innodb=ha_innodb.dll The plugin is located in BASEDIR/lib/plugin. But when I start the service I get the following in the error log: 140315 18:03:04 [Note] Plugin 'FEEDBACK' is disabled. 140315 18:03:04 [ERROR] Plugin 'InnoDB' init function returned error. 140315 18:03:04 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed. 140315 18:03:04 [ERROR] Unknown/unsupported storage engine: InnoDB 140315 18:03:04 [ERROR] Aborting If I comment both lines out then everything runs fine. Even when I try to run a plain MariaDB data dir (without the log files ...) the error occurs. Is there someone who have a hint for me?