About 1/3 of my network "push upgrades" from AVG 2011 to AVG 2012 are failing in a most spectacular fashion. About 1-2 minutes into the process, the network cards on the target computers go offline; the target computers lose all access to the LAN and the internet.
Trying to disable and re-enable them doesn't work, it spins forever. Restarting or shutting down isn't working, either: Windows gets all the way to the "shutting down..." screen and stays there forever. I have to do dirty shutdowns. Upon rebooting into windows, it may take several more tries before I can get the network adapters working again. If I repeat the process by trying once more to push-install the upgrade, same thing happens. This is across a variety of types of computers and network cards, not just one brand, and versions of Windows (32 bit, 64 bit pro, ultimate, etc.)
If I copy the AVG 2012 installer from my AVG server and run it directly on the target computer, it works fine. However, this is very, very impractical.
Using a Windows 2008 AD controller with minimal Group Policy stuff going on. Windows Firewall is disabled by GP, and each user is an admin user on his or her computer.