When I click on something, sometimes it doesn't do anything

[Nano]

When I click on any button, sometimes it works, sometimes
it will just hightlight and not do anything. For
example, if I wanted to close my web browser, I would
click on the "x" and it won't do anything, but if I try
it a couple more times, then it will work.

 

[CWatters]

Do you also have problems selecting text in a document or similar tasks?
Perhaps it's just a failing button in the mouse? Can you borrow a friends
mouse to try?