edited buildings not saving in gem

[micro]

Hey guys, in a bit of a pickle here, the problem I am having at the moment is, when I copy n paste/move buildings, well when I go back into the map I have been working on after saving via f3, well they are not there, so I have to do it all over again ughrr, this has been happening over the last 3/4 days now, and its driving me potty.

Can someone please tell me how I can save in the gem editor, so when I go back into the map, everything I have edited including buildings, are still there.

I even gave my map a brand new title thinking that may work, but oddly enough its not even highlighted when I go to load it, its not even listed, like it has totally dissapeared.

I have never really had this problem before, so I can't understand why it is happening now.

Thanks