Fan shuts down, card over heats?

Howdy

I write screen savers using OpenGL, I’m just an amateur, but I haven’t had many problems.

I’ve been told by someone that when my screen savers run their video cards fan shuts down, even tho it still does the 3D acceleration. But the result is that it could damage their card. I’m told the card is a GeForce FX 5800?

Has anyone else heard of this? Is there some way around it? I’m told its a problem with the card, not my programs, but I’d like to be sure.

Thanks.