You've hit something other than the boards limit i think. Mine runs fine at 148 mhz, above that the ram craps out...You might also check your northbridge heatsink, my first A7V133 <died due to an unfortunate mistake during a removal of my PAL 8045> had its Northbridge fan die one day due to it being a crappy fan, however that board did hold 140+ FSB fine still...