I couldn’t remember when it got started, but I’d been annoyed by the Menu Bar being toggled on whenever my fat finger accidentally hitting Alt instead of Win.

This actually has nothing to do with Pentadactyl’s settings, I believe. Normal Firefox users wouldn’t have hidden menu bar but Pentadactyl user would, and that’s irritating when the menu showing up, which I absolutely have no use of.

The solution is to change ui.key.menuAccessKey from default value to 0, you may also want to change ui.key.menuAccessKeyFocuses from default true to false in about:config.

Basically, the former is the one should be changed, but you will need to restart for latter to be false, or you can manually change by yourself. If you only change the latter, it would be reset when Firefox restarts.

I can’t believe how long I’d been tolerating it.