X40 USB ports

[kadf88]

I know the X40 has two USB ports, one on the left (with the proprietary plug) and one on the right.

Anyways, last night, i was plugging in a USB mouse into the right side port but it said unrecognized, but then i plugged it into the left hand port and it says its ok..
its weird, my USB thumbdrive works on the right hand side plug..
just not my mouse, is this because one is powered and the other is not?