Are that the only navigation keys that aren't working?

• https://support.mozilla.org/kb/Keyboard+shortcuts
• https://support.mozilla.org/kb/Mouse+shortcuts

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the extensions or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance/Themes).

• Don't make any changes on the Safe mode start window.
• https://support.mozilla.org/kb/Safe+Mode

• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

All other Keyboard/Mouse Shortcuts are working. Deactivated Add-Ons/Safe-Mode, HW-Acceleration and used Default Theme, no change.

Command + Ö at least activates the menu, Command + Ä has no outcome what soever.

Which Firefox locale do you use?

There may be a problem with the shortcut key definition if some aren't working.

German

I'm not familiar with the Command + Ö and Command + Ä shortcuts as they aren't listed.

Do the commands listed for the history B/F action in the Knowledge Base article work?

Yes, Command + Left/Command + Right works. Maybe the labels should be changed to this values in the german translation?

I tried US-English and German localization of FF 13. The keyboard shortcuts do not work, neither back nor forward. Command + Left/ Command + Right is no option for me.

I found out that the shortcuts work once the menu is opened, but they do not work when the menu is closed.

Also does not work in FF12

I have OSX 10.7.4

Any hints?