Summary: In Tiger, I used the F1 key as a Mail application-specific shortcut for the Get All New Mail command. However, this keyboard shortcut won't work anymore. I can set the keyboard shortcut in System Preferences, and the new shortcut appears in Mail's Mailbox menu, but the F1 shortcut doesn't trigger the Get All New Mail command. Steps to Reproduce: 1. Clean install Mac OS X 10.5.5. 2. Set up Mail with your email accounts. 3. Quit Mail. 4. Launch System Preferences. 5. Select the Keyboard & Mouse pane. 6. Select the Keyboard Shortcuts tab. 7. Scroll down to Application Keyboard Shortcuts. 8. Create a new shortcut for Mail.app. 9. In the Menu Title field, enter Get All New Mail. 10. In the Keyboard Shortcut field, enter F1. 11. Quit System Preferences. 12. Launch Mail. 13. Open the Mailbox menu. 14. Notice that the keyboard shortcut listed for Get All New Mail is F1. 15. Close the menu. 16. Press the F1 key. Expected Results: Mail checks for new mail. Actual Results: Mail doesn't check for new mail, and I hear the 'thunk' error sound. Regression: This issue did not occur in Mac OS X 10.4.11. Notes: I also tried F2 for Get All New Mail, but that didn't work either. However, I am able to successfully set and use function keys as keyboard shortcuts for other menu items, such as Apply Rules and Activity. 22-Oct-2008 Jeff Johnson: I've attached the screenshots "keyboard.png", "shortcuts.png", and "mailbox.png" to show my settings.