Copying and Pasting a map to a new file should be done with caution, you could easily end up with the entire thing off grid.
Do you check your compile log after a compile to find potential problems? A func_regenerate around the whole map could easily cause a leak if the origin of the brush is outside of the enclosed spaces in your map, but this kind of error would be reported in the compile log.
Yh I did check the compile log the only problem was the water texture.
func_regenerate's have no origin, no way you're going to leak a map with that
Chances are, you either left the func_regenerate as a world brush or a func_detail, and thought it was a func_regenerate.
Sorry forgot to mention it was prob a world brush
