Artifacts from Sony D8 camera

[lenl1]

I had recently recorded some family events, aprox. 90 Min. When I was capturing to the computer I noticed horizontal block strips randomly coming up only when the camera was moving. If it was still the picture was fine. I know its the camera doing this but I dont know why? Its the first time I have seen this. Usually all is o.k. I did use a previously recorded tape - Hi8.
Any ideas?
Sony DCR-TRV720 ntsc

Thank you
lenl1

My System
Asrock K7S8XE+ M.B.
Front side bus – 2x 200 (400 MHz data rate)
Memory bus speed – 2x 200 MHz (400MHz data rate)
AMD Athlon XP 3200+,
512 MB DDR-SDRAM, 3200
ASUS Radeon 9600XT
Soundblaster soundcard
SIS Raid 0 (2 Seagate 80 gig)
IO Magic DVD +- R / +- RW 4X
ADS Pyro Firewire card
Windows XP Pro. ( sp1)

[mits]

Hi,
If the horizontal block strips are noticable only during capturing and not when you play back the capturted clips then just ignore them. Its probably an inability of the capturing app to follow the action and at the same time to display it on the overlay window.