Ambiguous shortcut errors in Igor 7

Hi,

After upgrading my code, I can no longer use a CTRL+SHIFT+1 shortcut. I get the error

  Ambiguous shortcut: Ctrl+Shift+1

and then nothing happens.

When I comment out my menu entry

menu
    "Open panel/S1", /Q, DoWindow/K myPanel; myPanel()
end

then I get no response to CTRL+SHIFT+1. Shouldn't ambiguity mean I have 2 options for this menu entry?

There is still the line         "Test/S1"                       // Shift-Cmd-1, Ctrl+Shift+1. in the help so I don't think this behaviour should have changed in Igor 7.