When you say Final Cut V6 do you mean V6.05? Grab the updates from
Apple's site.
Your Audio/Video capture settings sound as if it should work fine:
Capture Preset: HDV-Apple ProRes 422
Have you tried to use another device control preset? HDV Firewire Basic for example.
All the best,
Ben
Curious Turtle Pro Video
Training | Editing | Support
Out Now - Film Wash Color Effects Vol. 3
for After Effects & Apple Color