Cannot Hide {This App} or Hide Others

Question

For one of my users on my Powerbook running 10.4.7, I suddenly cannot hide the current app or hide the others because both lines are disabled in all apps, regardless of how many apps are running. When I switch from one app to another, no window of the first is visible when I'm in the second. Preferential Treatment says that I rehave no corruped plists. Applejack reports that everything is OK after booting into single user mode. I can find no item in any plist using PlistEdit Pro that seems related to the problem. Also, the problem does not exist if I logon as another user.
I've backed up the fubared system and restored another backup. However, since this is the second time this has happened to one of my machines, I'd like to know why it happens and how to fix it with something short of major brain surgery.
P15" Powerbook G4 1.25 GHz   Mac OS X (10.4.7)  

Answer 1

Hi, clewis303. Welcome to the Discussions.
You wrote: "I suddenly cannot hide the current app or hide the others because both lines are disabled in all app"1. Just to confirm, do you mean that the Hide and Hide Others choices in all applications' application menus are unavailable (greyed-out)?
2. Do the keyboard shortcuts for Hide (Command-H) and Hide Others (Command-Option-H) still work, despite the fact that the menu choices are unavailable?
3. In the System Preferences > Speech > Text to Speech tab, if "Speak selected text when the key is pressed" is selected (checked), then click "Set Key..." and see if Command-V has been set as the keyboard shortcut. If so, change it: the default is Command-Option-F13.
4. In the System Preferences > Keyboard & Mouse > Keyboard Shortcuts tab, be sure no keyboard shortcut has been set to ⌘H or ⌘⌥H. If so, either:• Change the shortcut to another: click the value in the Shortcut column, then press the desired keyboard combination for the new shortcut.
• Click Restore Defaults to reset all shortcuts in the list to their default values.5. An errant Startup or Login Item maybe the cause. My "Troubleshooting Startup and Login Items" FAQ can help you pin that down if such an item is causing the problem.
6. Are you using an external keyboard with your PowerBook? If so, does the problem occur if you startup without the external keyboard?
7. Are you using any third-party software for defining your own keyboard shortcuts? If so, see if this has redefined or disabled the shortcuts.
8. One of the applications you use regularly may be redefining these keyboard shortcuts or otherwise prohibiting their use. I suggest troubleshooting your regular, particularly third-party (non-Apple) apps by process of elimination to see if one of them is causing the problem.
9. If none of the above, after pressing Command-H or Command-Option-H fails to operate correctly, check the ends of these Console logs for clues.
Good luck!
Dr. Smoke
Author: Troubleshooting Mac® OS X
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