I've got this error too. I've been getting it for a few weeks now. I looked at that thread, doesn't seem to have anything that would solve the problem.
I know they can be ignored, but the fact that they're here makes a full system scan NOT show up as a clean one, and I'd really like my report to show that. Capt anal and all that. Plus the company I work for (since I do remote work) periodically asks for system virus scan reports, and I don't like sending them in with "Some files cannot be scanned".
The two files that throw the 42006 error on EVERY SCAN are:
C:\Users\Joe\SkyDrive\Documents:ms-properties
C:\Users\Joe\SkyDrive:ms-properties
It wasn't always this way - I used to get clean scans, but at some recent date (that I have no idea when) these two started happening. I rarely to never use Skydrive. I don't want to completely remove it, might have some future scenario where I'd need to use it, but I'd really like Avast not to show this on every scan report. Any ideas?