Every time? And it's more than just a little static zap? I'm not an electrician, but if the actual case is giving you an electric shock it sounds like maybe there is power running on your ground line. A UPS will regulate the power going into your computer but I think it's going to expect a regular ground line. You might try an outlet tester like this:
http://www.tigerdirect.com/applicati...983&CatId=1795 to test the outlets where you are having problems. If the problem is just too much power going into the computer like you said, then a UPS should take care of that. It seems really fucking weird that it would be feeding it enough power to zap you from touching the case without frying any of the components first though. But like I said, I'm not an electrician. If your power is fucked up you should get an electrician to fix it.