Geforce 8800 GTS 320MB Power Requirements

Hi

I am purchasing a Geforce 8800 GTS 320MB next week. I had a look on the web as to what the power requirements are for this card and most web sites mentioned that one requires a minimum power supply of 400W with 26A output. I currently have a 400W PSU, but with 20A output on the 12V rail. I had a look a other power supplies (from 500W up to 1000W) like Antec, Vantec, Enermax, Thermaltake etc. and they all range between 18A and 20A on the 12V rail. Isn't there a possibility that the "26A" rating is a rating combined from all the other rails put together. Because I couldn't find a power supply with a 26A rating on the 12V rail alone. All that I can think is that all the rails' outputs measured together can give one 26A. Could someone please shed some light on the situation please. The spec listed on my PSU:

AC Input:
230V 50Hz (5A).

DC Output:
+3.3V : 28A
+5V : 40A
+12V : 20A
-5V : 0.5A
-12 : 0.8A
+5Vsb : 2A Peak : 2.5A

+3.3V & +5V : 225W
Total Power Max : 400W

Could someone work this out for me and let me know if this PSU will work?