How can you burn at 8x using 4x media with LDW-851S? I tried to use TDK 4x DVD+R(RciohJPN) and Nero only shows 4x as max speed. Do you need specific 4x media for Nero to let you burn at 8x? Is it even a good idea to burn at 8x? Is my P4 1.8 GHz, 768 RDRAM, WinXP fast enough for 8x burning?