Copy entry in terminal menu not accessible via menu key-C

1. Open new terminal window: gnome-terminal --disable-factory
2. Select some text.
3. Press the menu key.
=> Menu is displayed with first entry selected (Open Terminal).
4. Press C.
=> The selected entry is unselected.

Expected result: Copy in the menu is selected and the selected text is copied into the copy/paste buffer and the menu is closed.

You can also select a different menu entry with the arrow keys after step 3 and get the same result, unless you select "Close Window", in which case step 4 selects the "Copy" entry, but does not execute it and close the menu.

With the following command menu copy works as expected:

UBUNTU_MENUPROXY=0 gnome-terminal --disable-factory

gnome-terminal 3.4.1.1
Ubuntu 12.04.1 LTS