Have you used the crack so that you don't need to activate? That kills the PSCS ctrl-shorcuts, so you would need to remove it and probably activate immediately. If that isn't the case, and if you've tried checking for new drivers for your keyboard if it's a programmable model (even with a different one connected the driver could still have been active enough to cause problems), then try disabling helper/background programs (chat and so on) which have their own hotkey combinations.