Hi I've been using a Pioneer 107d for about 4 months now without any problems , however yesterday it started burning coasters one after another and also causing swirl marks to appear on the bad discs, I'm using Ritek G05 8x media and never had a problem with them, I thought maybe I had a bad batch but I then tried a TDK 4X DVD+R and it also coastered and has these same swirl marks

, Should I just assume its bad or anyone have other ideas, One other wierd thing I noticed is both Nero and DVD Decrypter wont let me burn any higher than 4X since this started happening, I'm using the latest official firmware .. Thanks in advance
Heres a pic of one of the burns.
