Same for me on my win7 32bit (Starter Edition) on my netbook.

@ densolis
Given that you are also experiencing issues thunderbird (no problems here with TB and avast), I just wonder if this isn’t some sort of conflict with another security application.

Have (or did) you another Anti-Virus installed in this system, if so what was it and how did you get rid of it ?

What other security based applications do you have installed (e.g. anti-spy/malware, firewall, etc.) ?