Video screen blacks out and scrambles during capture

[automaster]

As I am capturing video from my JVC camcorder using a firewire port, the whole screen momentarily goes black for a second then comes back. It will do this several times throughout the capturing process progressively getting worse. At one point it when the screen went black and came back, the preview window froze while still capturing and would update every 8 seconds. After about 45 minutes of capturing the screen went black for the 1 second and came back on. When it came back on, the screen was slightly scrambled, and the computer became unresponsive. I tried this several times getting really frustrated. I tried previewing the clips that did capture successfully, and the screen would cut out intermittently at different time during preview, but didn't lock up.

I reverted to ulead Videostudio 7 and had no problems at all. Can anyone help me?
I have a KT400 Dragon mb, Geforce fx5200, 1 gig of ddr 333mhz ram, three hard drives, each 40 gb., firewire port, gv-800u JVC camcorder.