I just tried to change my video card from an ATI 4850HD which doesn't support background draw for some reason, at least not in Vue, to a Nvidia GTX470.  However, my 1000W power supply apparently can't handle the nvidia. 

I really want to get background draw working, as painting mats in the terrain editor does not work without background draw.

So, I have a nvidia 8600GTS laying around.  Although it is not as fast as the ATI, would it be beneficial to just switch to this card?  I do not play many games.  What games I play are like solitaire.  LOL.

Well it can use up to 251 Watts of power form this site's tests
http://www.hardwarecanucks.com/forum/hardware-canucks-reviews/30321-nvidia-geforce-gtx-470-review-29.html

now unless you have a hell of a lot of stuff plugged in as well...yer 1000W PSU should be ok.
I have a 610 W in my art rig, now it' solder, but
6600 Quad core Intel CPU
ASUS Striker Extreme Mothebroard
3 1 gig hard drives
DVD writer
Nvidia 9600 GT card, and it works like a charm :)

sure it's the PSU and not the card itself? info suggests it runs hot, hence it's enormous internal heat sink

It's the only thing i can think of.  After switching cards, all the PC will do is power on, then recycle power.  Never get a BIOS screen even.  This was the second card i tried with the same symptoms so i don't think it is the card.

I have 4 1.5 TB HDs, Bluray ROM, and a DVD burner.  I also had an audio interface that is powered bt USB.  Also, 3 external self-powered USB HDs. 

I recently replaced my 700W PS with this one when it had died.  I thought I had bought enough extra power. 

try unplugging the external USB drives, and the BluRay (just take ower plug out inside, all caveats apply), then check? :)

somethings draining a lot of power

OH! wait a minute...
what motherboard do you have? is it supplying the right voltage for the Video card? This is relaly important as some older mothebroards won't supply right voltage to the slot the video card goes on.
Check this one before doign the above procedure.

I have a Biostar TP45 HP motherboard with Intel Q9550 processor and 8GB RAM.  It supposedly supplies 12V according to the manual.

As to unplugging, they were unplugged when I tried unfortunately. 

I can live with the ATI.  I'll just have to switch between software OpenGL and fixed pipe as necessary.  It's just frustrating as my card should work.

try asking for help on hardware forums? :)
sorry I honeslty don't know what else to try :/

something's damn odd if it won't start

have you updated the motherboard BIOS and chipset drivers?

read this page please shows LED diagnostics on your motherboard whether it's gprahics card, memory or chipset
http://www.xbitlabs.com/articles/mainboards/display/biostar-tp45hp_4.html