Flash messed up.

I got Firefox under my Macbook, and every flash I'm looking at is really strange, it will not register my clicks.

Exemple: When I click in a flash video to start it, it does absolutely nothing.

It started to happen a few days ago and I did nothing special that I can thing off that could have trigger the problem. Any help?

I've got everything up-to-date, apart from Flash, which I don't know if Apple software update do update or not.