What version did you go back to ?
You would need to go back to avast 5.0.677 if your problem was with avast 5.1.889 or 5.1.864, e.g. version 5.1.xxx related.
You should also do a clean reinstall:
Download the 5.0.677 version of avast from filehippo and save it to your HDD, somewhere you can find it again. Use that when you reinstall.
- Download the avast! Uninstall Utility, aswClear5.exe
find it here and save it to your HDD (it has uninstall tools for both 4.8 and 5.x).
- 1. Now uninstall avast! (using add remove programs, if you can't do that start from the next step), reboot.
- 2. run the avast! Uninstall Utility from safe mode, first for 4.8 if previously installed and then for 5.x, once complete reboot into normal mode.
- 3. install the latest version, reboot.
If you can post the link to the other topic.