Hi all, I 'am useing a mac and with its osx software and just up-graded firefox 8.0.1 yesterday and now find the link scanner in avg does not work any idear's

Probably FF.. I reckon it's not been tested properly and so disables anything that could possibly cause problems (had this with a few addons when it upgraded me to 5.. all it needed was someone to put in the code to tell FF that it works!)

I had a problem with firefox running slow and using a lot of system resources - Changed to google chrome

No more issues

Yesss!
Also, why bother with AVG?
Microsoft essentials is quite Good in XP (a helluva lot better than AVG ! )and Very Good indeed in win 7.
It's FREE as a bonus. IMO there is no need to use anything else.. ever.. on a home PC.