Disable Shift Cmd Q for logout

The following works for me on 10.9.5:

1. System Preferences > Keyboard > Shortcuts > App Shortcuts.
2. ‘+’ to add a shortcut
3. Application: All Applications
4. Menu Title: Log Out [Your Name]… Here, copy the exact text shown in the Apple menu, replacing [Your Name], and note that the ellipsis … must be typed with alt–;
5. Keyboard Shortcut: ctrl–shift–cmd–Q (or whatever you prefer: something different to shift–cmd–Q)
6. Log out and in again.
7. Note that the keyboard shortcut has changed in the Apple menu, and shift–cmd–Q no longer triggers the menu.