I think it's a good idea to work your way up slowly here. You know your CPU is okay at around 2.9Ghz@1.55vcore so it's most likely the ram that's unstable. Start at around 240 FSB and work up from there, checking stability every 10-15Mhz increases. Then you've got a much better idea of what's going wrong and where. Also, the 2.6 vdimm looks a little low. How high is the ram rated to go? Maybe try upping this is it's within specs.
It'll take a little time doing it this way, but in the long run it's almost always quicker than just guessing at a config.