I know this sounds silly, but try flipping the mouse charger's AC adapter
such that the positive and negative leads are swapped (ie: unplug your AC
adapter, rotate it 180 degrees, and plug it back in). The AC adapter has
equal sized leads, so one would assume that the orientation of the adapter
does not matter, but I was experiencing the same problem and it seemed to be
fixed after flipping the adapter. Why that worked (or even if that truly
did) is something I can only guess at, but at least it's something to try.