I have a Sony DRU500A running on the following spec: AMD 2000+ 1.5 Gig Ram x2 160Gig Maxtor UDMA166 5400RPM x1 40Gig Maxtor UDMA100 7200RPM Window XP The problems is - I can't get the DVD Recorder to burn at x4 - I have flash the drive to v2.0f and I have tried using several x4 brands: 1. Datawrite Classics x4 (Red Top) 2. Datawrite x4 (White Top) 3. Ritek X4 (Silver Top) And they all burn at x2 I have tried various Burning Apps with these brands at x4 and they all state initially 15mins for a 4.7Gb DVD-r but then end up saying 30-25mins. The apps I've used are: 1. NeroBurn v22.214.171.124 2. RecordNow MAX v4.50 3. CopyToDVD v126.96.36.199 The puzzling factor on this, is that a colleague of mine has the very same drive (bought together - same batch). Has only got firmware rev. v1.0g and has burnt successfully at x4 on the above brands and used the above applications (same rev.) If anybody can give me some insight to why it's not burning at x4 on DVD-r I would be grateful.