I answered your grass email question just a second ago, but need to add this:
If you are working within one location, all mapsets for that location have
to reside in the same place.-N.
Creative use of links and mounts can make GRASS believe they are in the same
place, when in fact they may be elsewhere.
In fact we have some of our mapsets on two machines in Berkeley, California
mounted on a machine in Sacramento. All of which is treated by GRASS as
mapsets under one location.
Sue Huse
REGIS
UC Berkeley