This won’t be of much help or comfort but I am on my second Pioneer 108 drive because of the same issues. I spent two weeks messing about trying to get the first drive to burn at more than 4 X on many different types of -R & +R media in 4 different PCs without success. I have tried the following:-
Checked the DMA at UDMA4 and UDMA2
Checked various ASPI layers from 4.60 to 4.72
Uninstalled and reinstalled ATAPI drivers
Uninstalled and reinstalled Nero, DVD Decryptor, CloneDVD and other recording software
Changed the IDE cables
Used the Pioneer 108 alone as a Master Drive.
The first drive went back to OCUK and they test all returned items before sending out a replacement. If they don’t find anything wrong they charge you for the pleasure.
When I received the second drive I was extremely disappointed to have all the same problems. The only difference with the replacement drive is that for some strange reason NERO will simulate an 8 X burn in 7 mins and 52 seconds but actually write in 15 minutes and 25 seconds. I have been using Arita 8 X discs (Ritek G05) which is the same disc that Pioneer put their name on for their own brand.
It’s all a bunch of crap really. I have 2 Plextor drives that burn flawlessly at 8 X and a Pionner 106D that writes at 4 X quicker than the 108!!!
I can only assume and hope, judging by the high number of posts on the same subject, that there are a lot of duff drives out there because in 4 weeks of reading and subscribing to a number of forums I am nowhere nearer to solving this problem… Somebody prove me wrong please…