Ouch - so that bug is
still there? I posted about it several patches back, and had hoped it was resolved. I'd suggest mailing the relevant files to Illwinter, but I don't think they're doing anything with Dominions 2 anymore.
Lost a phoenix very early in a MP the same way, so I know what you mean about being crippled. I think since then I have subconsciously avoided sending immortals to take provinces that are only dominion 1, which is when I think it happens.