iirc, a Debian patch made the change to loadunimap.c:
-static char *unidirpath[] = { "", DATADIR "/" UNIMAPDIR "/", 0 };
+static char *unidirpath[] = { "", DATADIR "/" TRANSDIR "/", 0 };

that shouldnt be an exclusive change, it should be both dirs.  the attached 
patch fixes things.
-mike