This is probably a common problem. My old system box is live with a tiny voltage. I can touch it, and keep touching it, though I am worried about the mobo and the hard disk. I recently noticed that my hard disk was also live. I belive this is a problem with not properly earthing the unit. Any ideas on how to solve this?
This is quiet normal for all apparatus enclosed in a conductive casing. I arises because of small capacive coupling from the AC power inlet to the PSU casing. Usually its harmless, but I recommend you use Ground connection to get rid of the charge.