Hi all. I am can not register avast free edition.
Old version (7.0.1426) - work fine.
New version - pressing Register (form - Wait) and occurs nothing.
Proxy - squid. Rules - "allow to avast.com ". Doesn’t require authorization.
Updating version programm and AV base - fine.
The proxy settings are registered in IE.
In squid logs - all MISS.
ps. I am sorry for my bad English.
I’m not sure, but if you set the avast! Update settings for the Squid proxy and not for the automatic (IE settings) one, maybe it helps.
Have a look at this thread:
Try avast GUI>Settings>Updates>Proxy settings>Direct connect “no proxy” 
That thread related to an older release which was corrected in a later version.
Most of us use “direct connect no proxy”
Yes, this bug fixed in avast 7.x version.
But, it will COME BACK in 8.x releases.
ps. как они его тестили… наступили на те-же грабли…