Lion Fullscreen Active Corners don't work

I am using P7, and Lion - both fully updated as of today 5/2/12.

I use Ubuntu, Windows 7 and Windows XP hosts under Parallels for Mac.

I hate the way the Parallels OSX menu appears immediately when the cursor goes to the top of the screen (Fusion has a couple second delay FWIW and works well). I read here that I could enable Active Corners and it would ensure the OSX menu or dock would never appear in fullscreen. Works well.

However the Active Corners I have set do NOT work. I have the upper and lower right hand of the screen set to show menu and show dock. They never do so. I did have it work one time when I tried it in Windows 7, but never in Ubuntu. I thought it was an Ubuntu issue.

Is this a known bug/issue? Am I doing anything wrong? I've tried uninstalling/reinstalling tools - setting and unsetting fullscreen options - changing Active Corner assignments. It just doesn't work.