Excellent! Thanks Andy, problem solved...
but I like AOS since it helps prevent tracking and keeps me from dodgy links! I'll just disable / re-enable AOS any time I need to download Flash. Here's hoping that the avast! team can come up with a fix for this as it seems like an unfortunate bug, and it will be a major pain if AOS prevents users from downloading safe software on certain browsers.
Anyone with tips on a long-term solution to frequent flash crashes with firefox, they will be most welcome.
Cheers again Andy,
MP