I seem to have picked up a very minor but visable drop on playback only. With my (new) spec aimed at editing I'm surprised really, all ideas would be very welcome.

Spec:

Adobe Premiere 6.1
Windows XP home, Winswap on own partition
Pentium IV 2.53 running at 2.66 (PR 2924)
GA-SIN XP1394 with mainboard firewire and PCI firewire
SiS655 chip
Matrox Parhelia 128MB
1023MB DDR - SDRAM
120 Gig 7000 NTFS Firewire drive (rushes only)
All drives/ partitions defraged often using PerfectDisk6 no spyware on machine, start-up programs minimul, exiting Zonz Alarm makes no difference