I've never had any problems with hard drive/mobo setup but have recently had several with duff memory - you could try slapping in some different (hopefully proven in other systems) memory.
Otherwise try flashing the BIOS - I know its a bit late but personally I wouldn't recommend Jetway mobo's - far better to pay the bit extra for well known quality brands such as Abit, Asus, Gigabyte etc.
Good luck with your probs, hope you get it fixed.