Weirdness

[Morbius]

I've been experiencing some strange occurrences recently:

Letters randomly disappearing when using the shuffle function.
Getting the 'you must use the (central letter)..' message, even when I have used it.
Words entering themselves before I've hit the enter key.

Has anyone else had experiences like this?  It all seems very weird to me. 

[mkenuk]

I had very similar problems about a year or so ago.
Someone suggested changing my mouse - I did and it worked.