was this the one you bought?
Newegg.com - PNY VCG88GTS5XPB GeForce 8800GTS (G92) 512MB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready SLI Supported Video Card - Retail

Since your having problems with that power supply, i recommend this one.

Newegg.com - OCZ GameXStream OCZ700GXSSLI ATX12V 700W Power Supply 100 - 240 V - Retail

yep thats the card i was lended, i aint changing the psu, i dont think its the problem, but thanks anyway, im gonna send the card away to xfx, still any theories as to why the pc makes the noise would be appreciated.

like i said, its probably the power supply. one way is to move the power supply to another computer, and see if that comptuer does the same thing. It could be a processor fan problem though.

even though its a completely new power supply?? also on closer inspection i have come to the conclusion that the sound is coming not from the psu but from the lower part of the system, around the gpu and motherboard

hmmm.. its not the graphics card fan? Check the processor fan. when you hear the sound, stop the fan with your finger (being careful, it can hurt =P ) and see if it goes away

Stopping any of the fans does no difference, this noise only started to happen after my pc went beeeeeeeeeeeeeeeeeeeeeeep when i turned it on once, the pc shop said it was the power supply and then i got a new one, could this have damaged the card? or maybe the pci-e bus or southbridge?