i myself, decided not to oc, and just to spend 300-400bucks to go with ddr2 800, the board anandtech reviewed for the core 2, and a e6300 core 2, its the cheapest solution, and it ends up being the best, because all i gotta do with my check after that, is replace the board with a high end one.(then again i fuxored my cpu oc'ing) normally with ram, the slower speed you get, like 333, the tighter the timings get. as in, at 400 you can run 3.3.3.5, with 333 you might run 2.3.2.4 or something of that nature
what you need to do is drop your ram speed to 133, that WILL NOT affect your cpu fsb speed, your ram speed and cpu fsb speed are seperate, thermaltake, is crap(99.999% of the time), they're loud and dont cool very well, they are for the most part, for show. thermalright the xp90, works very well and isnt insanely large, i have the xp120 and i rarely hit 40C, mostly mid/upper 30's. but this is also a very large heatsink/fan combo in a pretty big case as well. i also own both the xp-90(ran when i first got this comp) and the xp-120. both work very well, but the xp-190 obviously, works a little better.
and from now on, dont expect help from me if your not going to listen to anyone else.