I installed GRASS on WinXP using the setup file of the new version of WinGRASS from:
http://grass.osgeo.org/grass64/binary/mswindows/native/
When starting GRASS, as long as I point to an existing GRASS GISDBASE it works fine. But if I try to set up a new GISDBASE, new location and mapset (based on epsg codes) the "location wizard" fails, popping up an error window (as in the attached image).
This bug is something of a show-stopper since without a properly defined location GRASS will not start. Even if I start GRASS with the command line and try to run g.proj -c or g.setproj they also fail. So without jumping thru some tricky hoops, editting PROJ_INFO, etc. , GRASS is unusable.
Now, if I run the OSGeo4W installer and get 6.4.0svn, these problems do not appear. I can create a new GISDBASE and location, then I can successfully use that location to start either the OSGeo4W version or the WinGRASS 6.4 RC5 version.
Regards,
Micha