Bluetooth mouse blues

I've been having a few problems with my bluetooth mouse of late - it's really sluggish, clunky and almost unuseable. It's much, much worse when I copy files over my wireless connection - almost like it's suffering from some serious interference (I do have a serious amount of technology on the desk beside it).

It used to be fine - as smooth and precise as the cabled variety. I've not changed the surface it's operating on.

Any ideas?

 

Did that already...