I think you guys may have the solution there.
If the game loads for the French players with the renamed files with no errors, and you guys can connect without database errors, then the problem should be solved.
In terms of the interface files, they were probably updated with french text for the firecontrol, etc., so that's probably what the error message is from, but I feel good that it won't effect gameplay.
Thanks for keeping us updated!
Cheers,
David