Have my new Fireface 800 set up and it works fine when playing files on laptop's internal drive.  However, when files are played from Glyph Firewire 400 drive, there are hiccups and cursor jumps.  Drive is connected to Fireface 800 with (well-reviewed) FW400-FW800 cable.  Connection from laptop to Fireface 800 is approved TI-chipset expressscard with 2 Firewire 400 ports.  Had no problems daisy-chaining this drive before - could it be something with the 800/400 connection?  Maybe I have to do the registry fix and change speed to option 3:  400/800?  Does that affect daisy-chained hardware as well?  I am on XP Pro with SP3 - did not see speed listed and have not attempted registry fix.  The testing above was using Wavelab 6.  All of the "normal" performance tweaks have been done - network adaptors disabled, etc.  I can always look for an approved FW800 drive, but really like my Glyph!  Anyone had similar problems/any solutions?  Thanks!