9M-ISJ, yes AVG can really slow Radarbox down, as it virus checks every aircraft photo, etc. Hopefully your alerts will be more reliable, let us know what happens.
Blackthorn, the menus hanging, etc. has been acknowledged by Airnav. It's described in the bug tracking system as - "Some users experience slows down where menus cannot be used. Customers are usually on high end machines using Vista." It's got HIGH severity and URGENT priority, so I think they're taking this problem seriously. I've never had the problem myself, despite running Radarbox for many days at a time.
Note to Airnav - let me know if you'd rather I didn't post what's in the bug tracking system, but I think it's helpful for people to know the problem is being tracked.