It wouldn't surprise me one bit that Origin is blocking and changing how things work in TS3, so they can promote TS4. I have trouble with the Lifetime Rewards cheat and a couple of minor other ones not working, but the rest do work. Tried everything from Resetting Sims, to Renaming, to starting over, and only rarely can I get the Life Time one to work.
@Capt_Odee If you're talking about the clicking to add lifetime happiness points, that's always been a bit finicky and has nothing to do with Origin. Which other cheats don't work?
The Origin version of Sims 3 is exactly the same as the other versions aside from the pack selector and the mandatory Origin tie-in. Once the game is running, it's the same in any fully patched version (minus some obvious issues with the 64-bit Mac version). There's no reason a cheat would work in the disc or Steam version of the game but not when it's run through Origin.
