As far as I know the AI never "cheats" in the sense of it knows more then you or has more resources. It can however pull off some inhuman stunts, for instance if you assult a location on the map with cloaked forces it tends to comsat that location instantly about 3-4 times (however many comsats it has) even if it was in the middle of defending a base, building, and attacking some other place already. Course maybe some Korean pros can do it... seems inhuman to me.
As for knowing where your bases are, most SC maps are pretty traditionally mirrored and for the most part you can take a pretty logical guess as to where your opponents has started and their first 2 or 3 expansions without even scouting. There's really only a handful of non-traditional maps that are rather wacky (I think Newgettysberg is kinda weird if I remember correctly) that would throw some people for a loop. However even a human player has usually played those few ones enough to know where to look, so it's not inconceivable (to me at least) that the computer would logically know where you are.
But to answer the original question, no, the computer does not cheat.