Colored streaks on bootup

[SilverNexus]

Earlier today, when I booted up my computer, I encountered some odd color streaks (it was more streaky and grainy at the same time, and hard to explain) on the screen. I first noticed them at about the beginning of the Linux Mint boot (but had not been looking at my computer before that in the boot sequence, so it may have been from the start). On a black background, the streaks were green; on a white background, the streaks were magenta. Everything else continued as if nothing odd was happening.
After adjusting the monitor cables to no avail, I shut down my computer because the streaks were unbearably annoying, and when I booted it up again, the streaks did not return.

Is this an issue with Linux Mint (I have an NVidea GeForce 6200 on Linux Mint 14.1 MATE 32-bit), or is my video card preparing to kick the bucket?

Personally, I have a feeling my video card is nearing its end, but I want to confirm/reject my notion with more experienced Linux users.