Well I'll take a flier. Last year I had some Corsair RAM that ran perfectly well on an Intel mobo but when I swapped the RAM to a new AMD system, I got all sorts of errors, blue screens and lockups in games.
On the suggestion from a forum I tried downclocking the Corsair RAM on the AMD system and all my problems vanished. I replaced the Corsair RAM with similarly specced Patriot RAM and was able to run this perfectly well at its default and overclocked settings.
There was nothing wrong with the Corsair RAM but it was incompatible with the AMD mainboard at its default settings. You could try underclocking your memory by one notch. I repeat this is a flyer as others here have given you most of the mainstream advice for your problem.
I would comment that by choosing the 64 bit version of Vista you have chosen a much more problematic OS than the vanilla 32 bit version of XP. At present you get only marginal, if any, benefits from Microsoft's latest and greatest, complete with the "hunt the driver" feature.