Palit GTX 460 sonic 1GB not initiating display

I have following specs
Intel c2s E7200 @2.9Ghz
Gigabyte Mobo - GA-945GCM-S2L (very Cheap)(PCI Express X16 vesion 1.1)
2GB DDR2 X 2 (very cheap kukram)
Coolermaster 600W (18A@12V X 2)
Coolermaster Cabinet (Mid Tower)
22" LCD Display (DVI)
Windows 7 (32bit)

I had a 9600GT 512MB which was running fine and running all games at low to medium performance. But i purchased a palit GTX 460 sonic 1GB. it ran fine first but the next day the computer wouldnt boot and bios would give error, so i reset the bios by getting battery out but now there was no display on monitor and when i put the vga from monitor to onbord vga(D-Sub) it was booted into windows.
So situation now seems to be that card is connected to motherboard (both 6pin connected) and card doesnt takes display but my motherboard take the display. Please friends help me, iam on the verge to RMA the card or i think my PCI Express slot might have malfunctioned. Thanks in advance