As written above, the update line in the GUI refers to virus definitions.
Product updates are done through invoking the Update on the Market screen.
To get automatic upgrade to Avast, you can also check the box on the market screen to update Automatically. I did it before the latest release and indeed Avast upgraded itself.
1. Toshiba Satellite A75, Windows XP-Pro-SP3, Avast! free 8.0.1483, Sunbelt Firewall 188.8.131.52, Opera 12, mvps hosts, (MalwareBytes updated and run on demand only, rarely used)
2. Toshiba Thrive tablet (rooted), AdAway (hosts), Opera, Avast Mobile Security 2.0.4304 and DrWeb