GD module not installed with PHP 5.4.0RC6

[Marc]

My hosted is running PHP 5.2 in production environment and is offering a dev version of PHP (5.4RC6). I have to use this to get the calendar run within OwnCloud, but since that the gallery can't generate thumbnails. I allways get a "GD module not installed" error and there are no thumbnails generated.

Is there any problem with this development version of PHP? I think with the 5.2 version OwnCloud has generated the thumbnails.

Phpinfo shows me, that GD is enabled, even the Dependencies status within the admin panel shows my everything in green.

I'm running OwnCloud with mysql on a shared host at 1and1 web services.


Thanks for any help
Marc