Desperately need help with power requirements

Hey all,
Ever since I assembled my computer I have had some trouble with it. I am pretty sure that the video card is overheating (determined by the artifacting then crashing which dissapeared during the winter and reappeared once it got hot again) because the power supply is insufficient.
When i bought the video card, I thought my PSU would be sufficient, but it turns out the power requirements I was looking at in one place were different than what they were in Leadteks manual. Now I dont know exactly how the whole in series voltage amp thing works. I thought that you could add the amp numbers on 12 volt rails if they were in series for the amp requirements. For example this PSU has an output of:
+3.3V@24A,+5V@30A,+12V1@22A,+12V2@22A, -12V@0.5A, +5VSB@2A
The video card has a need for 12v@30A. Also my motherboard does not hold the processor fan in place well and it becomes loose when I transport it. Here is the machine.

PSU: ROSEWILL|RD600-2DB-SL 600W RT
MB: GIGABYTE GA-965P-DS3 P965 775
HD: 250G|WD 7K 16M SATA WD2500YD
VC: VGA LEADTEK | PX7800GT EXTREME TDH
CPU: INTEL|PD 930 3.0G 775 2x2M R
MEM: 1Gx2|CORSAIR TWIN2X2048-6400 R

Should this be working? Is my PSU good enough. Does anyone have a good idea for keeping the processor fan in place on my mb? I am going to try a few things and get some arctic silver. I really need help with this power supply/video card trouble. Or if somebody could suggest a setup that would make this work I would appreciate it. Thanks guys!

If you want the full explanation head over to the PSU section and look at the PSU 101 + 102 sticky. If not I'll explain a little. In order to find out the amps on the +12v rails, find the watts supplied to them. Lets take the Enermax model Gators suggested for example(which will work for you btw). Look at the sticker on the PSU. In the enermax case it supplies 420 watts to the +12v rails. Take this number and divide it by 12. That will give you the total amps on the +12v rails, in this case 35 amps. I'm not sure if your PSU will theoretically work because I can't find enough info on it. It probably would work if it were any other company other than Rosewill.

8O
Oops, my sinus pressure addled brain failed to notice that . Even still, it's Rosewill and I don't trust them as a PSU company. Now I don't now what to say...
8 hours of sleep sounds good.