Ok Craig. I've marrowed the problem down somewhat. It appears that if you load units into more than one transport then unload from one of them, it unloads all the units from all the transports from that one transport. So i have 2 transport units, i filled 1 with 6 units and the other with 3. when i unloaded the first, it unloaded 9 units. Now it gets slightly stranger, I then wondered what had happened to the units in the second transport, so I attempted to unload from this one to see if it would unload the 3 it should have had in it. Well it did unload them but it also made the additional 3 units that had been unloaded from the first that shouldn't have been, disappear as if they had moved from next to the transport they weren't originally put in but were unloaded from first and moved to by the second transport where they should have been all along. Does that make any sense? I can send you my little test map if it would help? Thanks Richard