I would say there is little point in chasing a possible problem in an old version.
So I would suggest an update, however, since you are experiencing a problem of sorts I would go further and do a clean reinstall.
Download the latest version of avast
http://www.avast.com/eng/download-avast-home.html and save it to your HDD, somewhere you can find it again. Use that when you reinstall.
Download the avast! Uninstall Utility,
find it here and save it to your HDD.
1. Now uninstall (using add remove programs, if you can't do that start from the next step), reboot.
2. run the avast! Uninstall Utility, reboot.
3. install the latest version, reboot.