I'm using the Engilsh-Dvorak keyboard-layout; My second keyboard language is Hebrew, which has nothing to do with Dvorak but the hot keys (e.g if I'm writing a document in Hebrew and want to make some bold text using Ctrl+b).
The default Hebrew keyboard that comes with Windows (7 and below) has a shift mode which matches each Hebrew character with its matching English QWERTY character ). Obviously I'd want to use the Dvorak corresponding key rather than the QWERTY one, so I created a Hebrew-Dvorak keyboard with a software called Keyboard Layout Manager (KLM) which creates new keyboard layouts DLLs.
It works just fine for the shift key, however, Ctrl-key triggered hot-keys (e.g Ctrl+l in FF) are being matched to the corresponding QWERTY key. I've examined the properly working English-Dvorak layout using KLM and in it's "Ctrl+ pressed" view, there isn't any character that's matched to any key but still I tried to encode the Hebrew Ctrl+ pressed keys to work with their matching Dvorak keys, yet it had no effect.