I use AVG as well...After I upgraded to the free AVG 9 I started getting knocked to desktop as well. Most annoying.
So I've been using Iobit's Game Booster (
get here ), a free app that suspends nonessential programs one often has running in the background (Skype, AVG and Java updates etc.) with two clicks once configured and it seems to have fixed the issue. Just be careful that you don't select anything Microsoft or any program that might BE essential; I had a couple of blue-screen-then-crash-then-reboots while I was fiddling with the programs to be suspended.
Besides, given that ROF is a resource sucker, it's good to free up as much of those resources as possible when running it. Afterward, one click will restore all those background processes. On top of that, GB has a tab to defrag individual game folders to keep them optimized, a nice little program.
Speaking of defrag, Iobit's Smart Defrag is another free app that works lots faster and better than the default Windows defragger. Using the 'Deep Optimize' option when defragging has been a help in keeping my system running smoothly for the last couple of years. Recommended.
[MF] Gunloon