Application windows randomly snap either to the top or bottom of the screen, and won't be budged I can move them from side to side but they're locked either at the top or the bottom and on some occasions side to side. It's never the same window two sessions in a row, but it is extremely annoying. It happens randomly and will continue to do it for that particular application window for the entire session if I log out and log back in it will be a different application window. It's the only machine that does it, we have two machines running 12.04, and it's also the only machine running the Gnome Fallback Sessions. Other than just don't use Gnome I need some kind of answer, the EU won't consider using any other desktop environment except the Gnome Fallback.
I think I had the same problem, for me the solution was here: http://earlruby.org/2012/04/getting-rid-of-self-resizing-windows-in-ubuntu-linux-12-04/
Those settings should NOT lead to that kind of extreme behaviour (I resize VLC to a tiny window - it snaps back to full height!), but turning them all off solved it for me.
I went through http://earlruby.org/2012/04/getting-rid-of-self-resizing-windows-in-ubuntu-linux-12-04/ and posted the steps here. I actually did that myself and it worked! Although that is a permanent fix for me.
Note: CompizConfig may leave you to an unusable desktop at this point. To fix that, revert all the actions by clicking the Backspace icon on the right of every action. Click back and try again. This is what my desktop looked like.
You are Done!