Thats dead on mate, your running your ram as close to its rated speed as possible, youve got pc8500 (1066mhz, = 533mhz double data rate) a 1.1 ratio with your fsb would have your ram underclocked at 450mhz meaning it would only be running 900mhz, this is assuming your running the 8x cpu multiplier.
EDIT: i see above you are on the 8x multi.
EDIT: i see above you are on the 8x multi.