Mouse pointer and wheel drift

[Fallingonion]

Hi all...

I've had a deskhop for a while now, and love it... currently running v0.70.
Recently it has started to exhibit slightly weird behaviour - after a couple of days, the mouse pointer and wheel no longer stop when you stop moving, but they keep drifting slowly in the direction they were travelling in.
If I reset the deskhop by removing the power and reconnecting, then it behaves itself for a few more days.

Anyone have any ideas what might be causing that, and how to fix it? I'm assuming it's hardware related... maybe worth resoldering everything?

Thanks all!