I had the same problem several weeks ago, and reverted back to Avast 8. Today I decided to try again (since Avast 9 has now gone through a few revisions since I last tried). I’m running Windows XP Home SP3 with no other antivirus programs.

I still have the same problem. I used avastclear in safemode. Then I installed avast using the online exe, which downloads/installs the latest files.

Still same problem…remains unprotected.

I give up. I uninstalled the latest avast and went back to avast 8, which works just fine.