It is hard sometimes to pinpoint the cause of a problem.
In a computer, when one of those tiny bits and bytes gets lost or corrupted, things go awry.
At times, the best we can do to correct the situation is replace a file, or reinstall.
If a way can be found to reproduce the problem consistently then we can come up with some kind of long term fix.
I will do my best. When more information is gained as to what might be causing the problem, the Avast Team will be informed, and hopefully a fix in the next version.
Techie