Easier and quicker to ask here - Please start a New Topic of your own here
http://forum.avast.com/index.php?board=2.0 (click the New topic button at the top of the page see image) and we will try to help.
Give an outline of the problem including any errors, etc. ?
And what happens if you tried a manual update from the avastUI, Maintenance, Update.
Also - Try a repair of avast:
XP - Add Remove programs, select 'avast! Anti-Virus,' click the Change/Remove button and scroll down to Repair, click next and follow.
Vista, win7 - Control Panel, Programs & Features, uninstall a program, select 'avast! Anti-Virus,' click the Change/Remove button and scroll down to Repair, click next and follow.
You may need to reboot after the repair. This has in the past resolved this out of sync issue between reported and actual VPS version.