I also have the Emprex DRW1008 8x dual form PC World (UK), appart from it being a little fussy when it comes to media and burning speeds, it has burnt all media I have tried in it, now using f/w 0658.
Imation DVD+RW (2.4x), from Argos. Great! burns at 2.4x
Mirror DVD+R (4x) From Poundland, London. Good! but burns at 2x
Maxell DVD-R (4x) From Poundland, London. Great! burns at 4x
Mitsubishi DVD+R (4x) From Poundland, London. Great burns at 4x
Memorex DVD-R (4x) From Poundland, London. Great burns at 4x
Self built system!
Jetway 867AS mobo
256Mb DDR 2100 RAM
60Gb IBM 7200 HDD
WinTV-PVR-350 Video Capture Card (hardware mpeg 1+2 encoder)
Nvidea GF4 440 MX AGP 4x 64Mb DDR
Windows XP Pro 2002 SP1a
Nero 184.108.40.206, Ulead DVD Movie Factory 2 (for authoring)
Emprex DVD writer is on Secondary master.
I have had no problems at all with this drive and system config