Also worth checking that the Tape is not damaged and the firewire cable and card are OK.
Pinnacle is also well know for its lack of reliability. Why don't you try capturing using Windows Movie Maker (assuming you are on XP.) If you sucessfully capture using this method then that proves that your CAM, and cables are OK.
Hope that is of some use.
COMPAQ something or other with 500Gb Boot Disk, 1Tb external Firewire Disk, 4Gb Memory and a super duper sound card, 19" TFT Monitor etc etc etc
Sony TRV33e : Sony TRV310e : Canon XM2
Sony Vegas Studio editions to v11
Remember, there is always more to learn than there is to teach.