Comment 25 for bug 937822

> The definitions for F10 are different (I expected that, I did that change) ->
> but they should not matter if the XKB events are identical (and they are!).

This is not completely true. The new definition of CTRL+ALT consumes Shift,
the old one does not. With the new definition, in a pedantic interpretation
of section 7.2.1 of the protocol specification of the X Keyboard Extension,
applications must not distinguish Shift-F10 and F10 anymore.

To see wether this is related to problem at hand, one could replace the
definition of CTRL+ALT (file in types/pc) with the following one:

   type "CTRL+ALT" {
 modifiers = Control+Alt+Shift+LevelThree;
        map[None] = Level1;
        map[Shift] = Level2;
        map[LevelThree] = Level3;
        map[Shift+LevelThree] = Level4;
 map[Control+Alt] = Level5;
 preserve[Shift] = Shift;
 preserve[Shift+LevelThree] = Shift;
 preserve[Shift+LevelThree+Alt] = Shift;
 preserve[Shift+LevelThree+Control] = Shift;
 preserve[Shift+LevelThree+Alt+Control] = Shift;
 preserve[Shift+Alt] = Shift;
 preserve[Shift+Alt+Control] = Shift;
 preserve[Shift+Control] = Shift;
        level_name[Level1] = "Base";
        level_name[Level2] = "Shift";
        level_name[Level3] = "Alt Base";
        level_name[Level4] = "Shift Alt";
 level_name[Level5] = "Ctrl+Alt";
    };

I do not have gnome on my machine, so I cannot test myself. Note that
the above definition is still not nice, but should be ok to check wether
consumed Shift is to blame.

> Returning to the previous version of F10 definition is not an option because it
> had clearly broken semantics of things like Shift-F10.

Do you have a pointer where the problems with the old definition are
described?