interesting image when cropping video...

we've got a couple edit bays running fcp 7 / studio over kona 3G cards. we're working on a project in 422 and when we have two video tracks over one another and when we begin to crop the top track we get this image on ref monitor.

it seems to me like a video card issue and i've reached out to kona but i wanted to ask if anyone had come across this issue before or was aware of it. after clicking outside of the video track but within the same sequence it seems to go away. just frustrating when you're working with clients and deliveries.

had to black out the label of the can being poored for nda reasons.

appreciate any help you can lend.