... And in addition to cutting/pasting the commands, could you also please include the output of the following:
$ 3dinfo -o3 FILE_UNDERLAY
$ 3dinfo -o3 FILE_OVERLAY
$ 3dinfo -o3 FILE_SOURCE
where the FILE_UNDERLAY and FILE_OVERLAY are the names of the files you are using as underlay and overlay (presumably the base file, whose space you were mapping *to*, and the output/prefixed file you were actually mapping). The FILE_SOURCE would be the file you had as input or source, to actually map *from*.
--pt
