<Solved> Firefox shuts down

[lsemmens]

I'm certain it's something I'm doing, but, for the life of me I cannot work out how.

Firstly, some background
I am sitting in a rocker recliner with a laptop on my knees and mouse on the right arm of the chair.

I just had a session with about 10 open tabs. I had to put my laptop down to go and do something. So far, so good. As I am about to sit down again I pick up laptop and grab the mouse to stop it sliding off the arm of the chair. Again, so far, so good.

Occasionally when I perform this task I might accidentally click a mouse button or two. Every now and then Firefox shuts down as I'm picking up the computer and mouse. Blowed if I can work out what combo I'm pressing to shut FF down.

Apart from the usual <Ctrl>Q, <Ctrl>W, <Alt>F4 key combos to shut down Firefox. Mouse is a generic 4button (left right, forward, backwards, scroll wheel) device and I can find no way to program those extra buttons, and that is not my desire. What else can shut down Firefox?

[lsemmens]

I just worked it out, I think. Mouse cursor moves to top RH corner of screen and I accidentally click. I hope that is all it is, Time to be more careful if I can.


edit: I have also set preferences to warn me when shutting down more than one tab.