Graphics cards compatible with IP-95 motherboard?

I have a machine with an ABIT IP-95 motherboard and a GeForce 7300GT GPU, and the GPU has recently stopped working. Since prices for the 7300GT appear to be higher than those for slightly newer cards, I decided to replace it with a 8400GS. This is a PCIe 2.0 card, but I was under the impression that that shouldn't cause problems. The new card doesn't work at all on this machine (there is no output to the monitor). After searching for a while, I found various forum posts (like this one) that seem to suggest that this motherboard is not compatible with PCIe 2.0 cards, but nothing definitive - can anyone confirm that? I can't even work out for sure whether the motherboard has PCIe 1.0, 1.0a or 1.1 - this Dutch post seems to say it is 1.0a?

If that is the problem, is there any way of getting the GPU to work with the motherboard? If not, how do I know what GPUs will work? Should any PCIe 1.0, 1.0a, or 1.1 be compatible? And can anyone recommend one that is likely to be cheap (and not a significant step backwards from 7300GT)? If a GPU just says it is 'PCI Express' or 'PCI Express x16' can I assume it is 1.x?