9800gtx+ with Corsair HX620w - Power warning?

Hi Ive just recently hooked up my mates computer with a new power supply as his old raidmax supply died. We believe it was to weak for the 9800gtx+ (ran for 6 months before dying). The new supply should be plenty.

Have hooked up the 2x pci=e 6pin connectors to the card. These should each have 18a across them equalling 36a right? The card requires 24a and minimum 450w psu. The rest of the set up involves:
1x 500gb sata 7200rpm
1x cd/dvd writer
Intel E8400 - stock clock
2x 2gb g.skill pc8500 memory
3x Case Fans
Vista Home Premium 32bit
Still think the supply ashould be plenty of power.

Was wondering if anyone could shed some light on why a message pops up telling us that the card may be underpowered and as a result the performance will be reduced to be safe. Have I connected it right?

Thanks heaps
Vance

If the motherboard has multiple PCI-E slots, there may be a power connector on the board labeled 'SLI/Xfire power' While It shouldn't be needed with a single card, it could be the culprit.

The extra 2 connectors are for 8-pins pci-e, some cards need 8-pins pci-e for power.

I have a hx620w with a 9800GX2, it requires 1x6-pins and 1x8-pins (6+2) for the power and never had a problem before.

The HX-620 is more than enough power for that system. Also, the entire system needs 24a, not the video card alone. 24a x 12v is 288w and that card uses nothing close to that much.