In order to effectively disable the Avira AntiVir, disable the Avira Service(s) and reboot the system. If you fail to reboot, it is likely the Avira filter driver will remain loaded and affect your results. Do the same when eliminating the Agritum firewall. If there is a conflict between the drivers of these applications, eliminating either will resolve the issue.
Alternatively, if eliminating either resolves the BSOD issue, you could open a case with Avira or Agritum and provide them with a Complete Memory Dump (not a mini-dump) to allow them to troubleshoot the issue.
http://forum.avira.com/wbb/index.php?page=Thread&postID=952500 discusses a BSOD with Avira and Agritum running on a system. It indicates the Avria product also comes with a firewall. Make sure you don't have both firewalls enabled.
G74SX-A1 - stock hardware - BIOS 202 - 2nd Monitor VISIO VF551XVT