I'm using Compiz, but not sure if that's the problem or not.

My alt keys are working fine, but I'm trying to do something particular with the Alt-Gr key for a custom Russian keyboard layout.

Glad to provide specific information on request.

Any help would be greatly appreciated.

Steps already taken:

1. I've gone into Keyboard Layout Settings --> Options, and made sure the correct Compose key option is set (at Right Alt).


2. Chosen my custom keyboard layout (from the Keyboard Layouts section) and then brought up the onscreen keyboard which allows me to check which key is being pressed with onscreen feedback cue.

Doing this indicates that my Compose key is indeed the right alt, and it does flash when pressed. It also indicates that in my custom keyboard layout is correct on the key that I want: for the z key I have mapped 'З' (pronounced "ze") and for Alt-Gr + z I have mapped 'Ж' ('zhe'). This information shows up in the onscreen keyboard. However, trying this key combination produces no text on the first press, and on subsequent (joint / combo) presses, this produces only the non-altered 'З', same as I'm expecting from the non-combo z press only.

In summary, the Compose key is mapped correctly, and the character I want is mapped correctly (all 4 options (2 letters each with upper and lower case) appear in the onscreen keyboard), but the combination does nothing (on first press) and then the non-altered thing subsequently.

This is what my usrshareX11xkbsymbols
u file looks like:
[...]
key <AB10> { [ U0417, U0437, U0416, U0436 ] };

According to the documentation I've seen, the first two entries should be produced by pressing the z key and shift + z respectively (I'm working in Dvorak, so that's the key just to the left of the right-shift key), and the last two should be produced with the Compose + z and shift + Compose + z respectively. But, as mentioned, the actual behaviour I'm getting with Alt-Gr is nothing and then the default z and shift+z behaviour only.