Comment 3 for bug 636632

I'm using the same setup and I'm not experiencing the issue at all. However, I'm using 32 bit so if you're using 64 bit then there may be an issue there. If not then there might be a conflicting app that is also trying to use the Super L key (Compiz-Fusion for example) which can cause issues like this. You may want to check your system and login start up lists to see if this may be the case.