Altium Designer "Copy Room" function not working properly
If I remember correctly, this was a nasty bug in Altium 15.0, where components were flippe on layer in some situations. This is through the "Flipped on layer" property, which was introduced in 14.3. This was a glitch, it should be fixed in  15.1.2 according to the release notes (6317    Undo of component layer flip no longer modifies the component's Flipped On Layer property.).

I don't know if there is a patched version of the 15.0.x release, because the release notes are no longer available (old releases until 14.3.x are archived, new documentation system starts with 15.1.x).

If you have access to a newer version, I suggest to try it.