Thought I'd give this a shot. I've been at this digital filmmaking for a few years now (started with the Targa 2000 back in '99) and feel like I know what i'm doing more or less, but I ran into this crazy problem last night...
WinXP SP2 machine, fully updated, 2Ghz, 1 GB RAM, working fine for a year (mostly using either After Effects, Premiere Pro 1.5 or Vegas for various video applications). I put a modem in the machine last year. Still no problems.
The other night, I take the modem out to put it in another machine, and all of a sudden, my IEEE1394 card is acting wierd. It doesn't want to preview out to the camera in either Vegas (BOTH 5 & 6) and Premiere. The strange thing, is that if I "print to tape" in Windows Movie Maker, it works fine.
It's not the card, camera or cable. I put all three in a different machine (a 6 year old Pentium II 400 Mhz) and I previewed fine from my old Premiere 6.5.