TV Capture question

I’ve been capturing video to burn to DVD. The image quality is fine, but I occasionally get a solid white line that goes all the way across the screen and occurs in a single frame. Any ideas what causes this?

may be wrong here but it could be one of two things anti copying stuff or the more likely
if its old footage like above scenes may have been spliced badly and reflect on the final cheap footage
i may be worng

It shows up on all programming of every channel, commercials, etc. while using the TV tuner as a regular TV. When I run the regular TV right beside it on the same channel, there are no lines. It’s caused by something in the computer but I don’t know what.

What is your capture setup. Hardware? Software?