Avira AntiVirus Premium has a serious bug. I reported this bug via telephone during November 2010 to the Avira telephone support staff. When I described the bug in detail the Avira technical support agent agreed that this was a very serious bug that needed immediate attention. Here is how the Avira bug works. I use the Avira AntiVir Premium to protect my pop3 email. My email client is Outlook 2003 professional with all security updates applied. Most pop3 servers uses port 110. Avira monitors this port apparently without any difficulty.
I also use Google gmail accounts that utilize port 995 as their pop3 gmail port. When I configured the Avira AntiVirus Premium to scan the gmail pop3 port 995 my email client Outlook 2003 encountered serious errors. When you remove port scanning for port 995 the errors go away. Unfortunately, this implies that if you use Google's gmail the Avira AntiVirus program will not be able to scan inbound emails making your computer highly vulnerable to virus attacks.
I also set up imap accounts to see if this would remedy the problem. It did not and this is why I cannot recommend the Avira AntiVir Premium as a serious antivirus product. Considering how much trash Avira has spoken regarding the thoroughness of their antivirus products I am very disappointed. As of December 09, 2010 the bug has not been fixed.