OK. I'll keep it down. I just don't like people I don't know telling me what to do.
Well, after the tray icon and UI never appeared again (ever!) I had to run avastclear in safe mode and re-install the whole thing. This time, it seems to work, even after a reboot. And I also got build 160 too.
It still seems like too much of hassle to me...Several reboots, installations/uninstallations, etc...