Graphics card stopping POST (I think)

Hi all

I have a graphics card problem. It started recently following the death of my RAID array, which has been running my system for a good 3 years now without any problems. 3 weeks ago my RAID array died (checked both drives and one of them cannot be recognised by any recovery tool) and ever since, the PC has had trouble getting through POST. When this happens, I notice that the graphics card has 2 red lights on the side opposite to the GPU (they're next to each other and when the system does boot, these lights go out). The motherboard has 4 diagnostic lights and they're all green, meaning it thinks everything is fine. The only way I can get it to POST and boot is to wiggle the graphics card (doesn't always work) or disconnect and reconnect the PCI-E power plug (also doesn't always work). My hardware is as follows:

Sapphire 4850 toxic edition
Zalman PSU (600W I think)
MSI P35 Platinum
E6600 Core2Duo
4GB Crucial Ballistix

Thanks in advance!