What does that mean to set it to native? By the way, that dll fixed the error and now I get the same result as before: nothing with pbuffer and audio only with fbo. I also set up the graphic card memory (I found that my card is 256+, so I typed in 256). Maybe, it's only the ati driver which does not work... What a pity! I really thank you for your help austin: you were a gold mine! ;) Merry Christmas (even though it's gone by now!)!