I have a Mac Mini. I also have a cheap optical mouse.
The two do not seem to be able to co-exist.
I've tested the mouse on a Windows PC. I've tested the USB ports of the Mac with the keyboard and another, similar mouse (but one which is rather terrible ergonomically).
Can anyone suggest things I could try to reolve this?
I've turned the Mac on and off several times but it's done nothing. Occasionally a mouse pointer will appear for a couple of seconds under the Apple logo in the top left of the screen, but it won't move and clicking has no effect.