On you personal iMac:
- Go to System Preferences > Keyboard > Select the Keyboard Tab
- Check the box next to "Use F1, F2, etc. as standard function keys." This way you do not need to hold down "Fn" to send the command to the remote system.
- Then go to System Preferences > Mission Control
- Double check that F11 and F12 are not selected in the drop downs as Keyboard and Mouse Shortcuts or "Hot Keys".
- If they are, CHANGE them to the "-".