Thanks for the update Pocus. Not sure if its related but you cant combine ship groups either. It just displays the same error message about 'one army per turn' ... like in the big 75 GC (as America) the 1st single unit of transports frigates you get then a few turns later you get the navy with 2 units and a leader, if you try to combine them it gives that error.
Im still to busy getting my butt kicked by the 1.6 AI to worry about this bug at the moment anyway

Dammmm ... its like you taught it to be psychic, and forget about hoping for a long siege now, if the AI thinks he can take you he will crush the defenders. Its made me really jumpy

and I have armies running all over trying to escape hehe.
Myros