Actually after posting thinking it was definately the mouse, the keyboard is still messing about, with Ctrl key appearing to stick (using the scroll wheel on the mouse the zoom level changes until I touch the Ctrl key. Must be the only keyboard with a Caps Lock AND a Ctrl lock! Think I'll treat myself to a new keyboard. I do have others but....
Is there any advantage of a USB keyboard over a PS2? I only have two spare USB ports, aside from the front panel ones.
The port is faster and they do seem to work better.