There is something fishy going on there.
Are you 100% sure you've got the latest version of the program? (right click on ball, About, it should be 4.1.357). Older versions may have the problem.
If you have it, I'd need you to run 'ashbug /setuplog' from the commandline (you must be in avast's directory). Write few words about your problem in the box, also put there your forum handle).
thanks,