yeah i've noticed that before a week.
this is kinda annoying, but there is no problem of getting through that..
- tell avast! to remember to let it run normally.
or.. do what i do.
- remove everything related to NOS (which isn't really neccesery to the system) and download adobe flash player offline (no need for NOS).
then, when it updates after the offline install, there is no NOS on the system.