Try using an extension cord between the MJ and the PC USB port so that you can move the MJ away. Also try changing the physical orientation of the MJ versus the PC.

As I sit here thinking about this, I wonder if your outlet is TRULY wired correctly and do you have some sort of ac protection that is creating a resistance in the ground circuit?

When I was young, I was Liberal. As I aged and wised up, I became Conservative. Now that I'm old, I have settled on Curmudgeon.