ok, so lately ive been having trouble with my desktop. it shuts down randomly. and nothing has been changed in it except taking out an IDE burner and replacing it with a sata burner. when it shuts down it completely shuts down, as if i pulled out the cord from the wall. so any help would be greatly appreciated. specs on the computer are vista ultimate amd 64 x2 4200 OCed to 2.52. 4 gigs of ram, even though its only seeing 2.75 of it. also, i checked the temps of the computer while its running and they seem to be fine, high 20's when ideling, mid 30s when doing something normal, internet, word ect, and low 40's when ripping a movie or something like that.