I use right-clicking a lot. A few times a day, though, it will just refuse to work. Seriously. What's worse is that the file above or below (in the bin) will show the contextual menu when right-clicked but the one I -want- to right-click on will not respond. And the issue is sporadic. Mouse is fine. Project is fine. Just. This.
I run into the same problem every now and then, but only with multicam sequences. I've never been able to hammer out a reason why though. I'd suggest submitting a bug report as I've heard that the amount of bug report submissions help determine which bugs get addressed first.