What do those purple lines in CS:Source mean?

[PcMe]

I get them on the ground and stuff during play, I'm assuming it's a video card problem; but is it bad? Because I play on high settings and no lag whatsoever on my 6600gt and only get the purple lines occasionally. They aren't lines like straight monitor lines, it's like landscape lines in the filling of the rocks in the ground, if that makes sense.
Thank you

 

[Chase]

Hehe, yea I get those occasionally as well, and what a cu-inky dink, I have a 6600GT too! Yea, I'm most certain that this is just a glitch with the card. It only happens to me when I minimize CSS then maximize to play it again and join another server. I'm sure Nvidia will eventually come out with a driver to solve it, and even if they don't, it dosn't make the gameplay any different. So, there you go, my spill, hope that helps!

::-Chase-::

 

[PcMe]

Oooh, that makes sense. I never linked it with that, it does only happen when I minimize it.
Thank you, Chase

 

[DJ-CHRIS]

It happens everytime you change video settings, and occasionally if you alt-tab out of the game.

 

[Riceball]

Yea it happened to me in HL2 a couple of times.