When we originally installed OF last summer, we had problems with webpages not loading unless Avast's webshield was disabled. Over time though the issue became sporadic and eventually seemed to resolve itself, and all was fine staying fully protected and monitoring with OF.
I just recently upgraded to Avast 5.0 and we're back to the same problem. I can hope it will "magically" fix itself again, but feel like there has to be some real information on what the issue really is. It seems silly that two high quality free security programs can't be designed to play nicely with each other.