Originally Posted by tinners 
Just one final clarification, if I set the memory to ddr-800 in the bios will this make sure it never goes past this speed even when pushing up the fsb ?
Nope, it will start the RAM off at 800Mhz and as your increase the FSB, the RAM speed will also increase, so unless you have PC2-8000/85000+, you dont really want to be doing that at this stage.