In FF 26.0a1 (2013-09-23)I get the contextual menu when I right click. This sort of ruins the whole experience -- though I suppose it's nice that you're not jacking my normal mouse behavoir.

Thanks for giving it a spin. Yeah - not the best experience I agree. I think the next round of improvements may be settings to toggle desired behavior. Some people may want the menus to remain, others may not, and so on. As always, I'm up for any other thoughts or feature requests!

update: disabled the menu for now, just for kicks.