avast doesn't discriminate against javascript unless it is detected as infected in which case an alert will be displayed.
Southpark's comment on different browsers and the inconsistency if the problem would lead me to believe that it is browser related, if it were totally an avast issue I would expect it to be consistent across all browsers.
It seems that it affected MSIE7 the most, Firefox works a little bit better (but not OK), Opera works fine.
Not that I doubt it is the same can you be more specific, what browsers have you tried, any example URL we can try, your firewall, your OS, etc.
I wanted to send you log file but your email address is hidden in your profile.
As I said - I couldn't get Windows Update to work (on any computer), System Restore didn't work either (as far as I know it uses some components from IE). WinXP machines have MSIE7, and Firefox 3 Alpha (after some pages didn't work properly I installed version 2 but it was the same) and Opera 9.2. Win2000 has MSIE6.
I also had problems with SMS messaging system (
www.smscity.net - but you have to login), couldn't vote on some radio station here and (as I forgot to mention before) router's control panel didn't work properly - for example when I was changing some TCP/UDP settings I couldn't select them in the menu.
Well, everything is OK now, thanks to Oldman's solution.