One thing you can try is to run an extension cord from a different outlet that may be in better shape. Also, maybe try a pc power supply with a battery backup. Even if its only a temp fix until you figure out what the problem is.
As far as the actual electrical problem goes, it sounds like you may have an issue with one of the legs in your homes ac. Its the kind of thing that makes you think you have all kinds of electrical problems/dropouts with your house, but its a relatively simple, quick part to fix. It can also explain why your Wadia ps may not be bad. Understand, though, I'm not an electrician and this is just a guess on my part.
As far as the actual electrical problem goes, it sounds like you may have an issue with one of the legs in your homes ac. Its the kind of thing that makes you think you have all kinds of electrical problems/dropouts with your house, but its a relatively simple, quick part to fix. It can also explain why your Wadia ps may not be bad. Understand, though, I'm not an electrician and this is just a guess on my part.