Yeah, I should have held off on that last post (but it was a good idea).
I've since tried updates of that mission in 1.41 and they didn't work.
I tried goofing around with it in the mission editor to find faults or update the 3D or the scripts. No luck but I managed to get the mission to load farther before it failed. That doesn't mean much, it still failed to load.
So, at this stage its much easier to say it isn't the fault of the mission- its more of a fault in 1.41.