Oki doke, in order to get around the fact that my dinovo mini will only send 1 key at once to the n900, I added the following line to usr\share\X11\xkb\compat\basic to give me sticky ctrl:

interpret Control_Lock+AnyOf(Control+Lock) {
action= LockMods(modifiers=Control+Lock)
}

I added this under the equivalent Shift_Lock {...} line.

Works a treat!

I read about how to do this here, some v. useful info:

http://www.charvolant.org/~doug/xkb/html/node5.html

Cheers

EDIT: Dagnamit, I've tried editing xkb-chinook in the same way and mapping my keyboard, it doesn't latch ctrl! (but the hw keyboard does)