I need some help with a psu..

[nd4spdbh2]

OK well here is the deal i have a nice quiet zalman 400w psu that i havnt used in a while because i remeber having a problem with it. Any ways i hooked it up to a socket a system using the usual hookups: atx for atx, 4pin for hdd, cd, fans, and gfx. like always... the system booted fine with absolutly no probs and ran for an hr straight till i turned it off to see if it would work in my server. now my server is not a power hungry beast its a

P4 3.0c
FX5200
Cd-rom
DVD burner
2 80gb hds in raid 0
1 200gb hd for storage

i hooked the psu up like normal and the computer turns on for about 10 secs then just powers off. the only way i can get it to restart is to unplug or hit the main power switch on the psu and then plug it back in then press the power button... Now why would the psu work fine on a socket a system and not on a p4 setup?

[nd4spdbh2]

ok well i tested the voltages when during the first 10 secs it is on and 5 and 12 volts are fine but the 3.3 gets down to 2.98 ... these readings were taken buy a multimeter.... could the 3.3 getting down that far be the prob.

I did find a cool lil variable resistor that is used to tune the 5 and 12v rails but nothing for the 3.3 :bang head ... rrr i really want to use this psu for my server and get rid of this loud pos icute psu.