occasionally, i'll be browsing and suddenly my right mouse button stops working within the page area, no right mouse click menu and no mouse gestures. at that point, it still works fine in other windows (even other FF windows); it even works in the tab bar of the affected window, but not within the page. unfortunately, i have NOT found a way to reproduce it on demand, so i can't narrow it down to any of the extensions i have installed. other tabs in the same window, either already opened or opened after the fact, are affected as well. i've noticed that occasionally i'll click the right mouse button to bring up the menu, but nothing will happen; clicking it again, usually brings up the menu. also, i use mouse gestures frequently, and i have noticed that occasionally when i perform the gesture to close a window, it will close the window and then pop up the right click menu. i've also seen it where it will execute a gesture spontaneously, as if i'd released the right mouse button (but i hadn't). this suggests that either something is actually generating the MouseUp event prematurely or FF is reporting and processing an event that didn't happen. under the circumstances, then, could this "phantom" mouse event be causing a problem with the MouseDown event handler for the right mouse button, either causing it to ignore events or disabling it entirely?