Hehe...bad ground again. My PowerBook has two different adapters for the charger/PSU. It has a 2-prong adapter for plugging the entire thing directly into the wall, and it has an extension cord with three prongs on it. If you plug it in with just the two prong adapter, it has a weird feeling to it. If you touch it lightly, it hums and tingles...but if you use the 3-prong adapter with a properly grounded outlet, it doesn't do it anymore. There was a computer at my old high school that wasn't grounded properly. The school had those big floor-mounted air conditioning units in the classrooms...and the desk this computer was on happened to be sitting next to the one in that room. The teacher had complained about the printer not working, so I bent down to have a look. I grabbed the printer cable to see if it was properly tightened...and I happened to touch the air conditioner at the same time. I got the hell shocked right out of me. I should have sued. Haha. Luckily, it just made my muscles spasm and gave me a bit of a scare. I didn't need any medical attention or anything.