DavidR
2
It is an indication of a problem with avast not directly your system, though it could be related. That said it may not be that serious otherwise I would have expected an error dialogue window to be displayed.
Try a repair of avast:
XP - Add Remove programs, select ‘avast! Anti-Virus,’ click the Change/Remove button and select Repair, click next and follow.
Vista, win7 - Control Panel, Programs & Features, uninstall a program, select ‘avast! Anti-Virus,’ click the Uninstall/Change and select Repair, click next and follow.
You may need to reboot after the repair.