Behavior Shield Broken

I have done two clean installs of my avast 6.0.1289 and the BS works for one day only and then the following day it goes back to showing 0/0. What could be wrong? If I update to avast 7 will it scan correcty or just for one day only?

Only You know the answer to that…if You install ???

The las stable v6 for Avast! was 6.0.1367. Why are installing v 1289 ? Did you use Avast! uninstall utility ? Is your system clean ?