Wow, you were right. I remeber to have verified a disc with lots and lots of read errors. It said for the secondary channel to be in PIO mode. Like the FAQ said uninstalling the controller set it to Ultra DMA mode 2 back again. Actually verifying the first 1x disc again. Going faster now. I checked the logs and I had Daemon Tools installed without problems with SPTD. I think I am going to install it back again but first I have to check if burning really works well again!!!
Thank you very much
BTW: Could it be possible to make a nice warning like the SPTD warning in a case of PIO mode usage of the controller?