General :: Enable Modifiers Via Xmodmap

I recently got a Logitech G11-keyboard for my Ubuntu 9.10 64-bit box. My question is xmodmap related and not restricted to this particular keyboard, nor to the distro I am using. The keyboard has a.o. 18 G-keys. These have been successfully defined in /usr/share/X11/XKeysymDB as per [URL] and I have a ~/.Xmodmap file that matches keycodes to the names in XKeysymDB.

My .Xmodmap definitions are rather simple, e.g. 'keycode 175 = G1'. So I do not define any value for modifier combinations, nor do I know how to do this.

And here's my real question. How should I define these keys so that the Crl-, Alt-, Meta-, Super- etc modifiers work with these keys?

With the current setup, the modifier versions of these keys do only work for the second keypress, e.g. the first Ctrl-G17 is perceived as a G17 keypress, and the second and remaining Ctrl-G17 presses are correctly received as a Ctrl-G17.

I would be happy to read an explanation of this behaviour, and even more so, about how to properly define them so that the base key as well as the modifier versions would be available.

If the odds are a million to one against something occurring, chances are 50-50 it will.

[URL] and go2 places!