I think you can rule out the cmos bat. I have a dead cmos bat in one of my computers at home, i just haven't gotten around to replacing it. It only has problems when i unplug it...as it should, since the bat is dead. I've had to replace bat's in older gateways at a previous job, as they went out, and we only knew we had a problem when we lost electricity for extended periods of time.
You might try taking the side off of your case, and putting a big fan blowing in to it. That should tell you if you're having heating issues. Also, if you think it's an issue with your psu overheating(or overworked...), you can try putting your hand by where the air is venting out of it (before taking the side off), if it's hot, then it's overworking itself (as compared to the other fans venting anyway). Take the psu advice with a grain of salt tho...It's hard to tell sometimes if they're the problem component.
<edit> One more thing...If the orange light is on...there may be a light code associated with your gateway. What you can do is head out to Gateways site and look that code up per your computer model id.
Current machines running F@H:
Athlons: [2000+][64 3500+][64 3000+][366][1.3x2]
Pentiums: [P4 1.4][P3 933][X 3.0][P4 2.4x5]
<P ID="edit"><FONT SIZE=-1><EM>Edited by apesoccer on 02/15/05 10:56 AM.</EM></FONT></P>