[Admins]

Ok worked a little bit on the problem.
Before the modification:
Geforce2: 110 milliseconds for level switch
Geforce 5900XT with 512mbyte video ram and latest driver: 300 milliseconds

After the modification:
Geforce2: 40 milliseconds
Geforce 5900XT: 50 milliseconds

The window size was a little bit smaller for the Geforce2, that's why it might still be some milliseconds lower.
It seems that the newer drivers take much more time for updating textures that are in the video memory, or they're more optimized for DirectX 10 stuff. It should be ok now though with the modifications I made, so with the next Graal version (next week) it should work better.