For some reason, my < > keyboard functions for rotating my screen won't work! I've tried shift-pressing, but it just makes it rotate non-stop. Anybody know how I can fix this????

This regularly happens to me. Do you have pets installed? (I think that ep and perhaps any after allowed you to rotate floor tiles). It seems to be rotating a floor tile and clicking on another build/buy catergory disables the rotate keys. If you go back to flooring and select a floor rotate it a few times then double click the back button (the one with the saw and paint roller on it). That should reenable the rotate keys.

If this doesn't fix it it usually means you've gone into neighborhood view while they were still disabled and if this is the case you need to restart the game to fix it. Its a massive pain and it doesnt seem to effect everyone.

This is the only senario I've identified that causes the keys to stop working and it's bothered me since pets came out. Hope that sorts it out for you, or that someone can come along with a better solution and help us both.