Strange Mouse Behavior.

So last night I installed my BFD eco, Zildjian pack and BFD2 Greatest Hits Vol. 1.
BFD works great with the Gen16 Zildjian but it can't seem to locate the files for Vol.1. I can find them on my HD but they're empty.
But that's not the issue. I'm sure I'll figure that out eventually.

The strange thing is that while playing around with my new cymbals last night I clicked on something in the BFD window. I think it was the 'Kit' or 'Mixer' tab and my mouse pointer disappeared. 
I could see the pointer down in the task-bar but if I'd try to mouse over X1 or BFD it went away.
It was still there in a way, just invisible because as I moved it around I could see things hi-light or those little pop-up thingys that inform you of what buttons, tabs, nobs and whatnot are would appear.
So with a little luck/skill I was able to close X1 and save my changes.

Anyone else ever have their pointer go invisible?
Any ideas what may have caused it? 
Or like me do you think it was just one of those off the wall, quirky Windows/PC things that just happen to make you wonder why?

Mike