oh dear.
i bought them from ocuk, so even more oh dear, ive been adviced to rma them straight to geil because ocuk will just stick them in a rig and run them on auto and tell me they are ok
it has been running quake 4 at 2.8ghz for 6 hours straight fine.
then i left it idle whilst i took a shower, came back and it had locked up (again) and now the only thing that will get it to boot is cmos reset (again)
the cmos battery and jumper are under the gfx card