gh_scm2newstr segfaults

[Levi <levi at top dot monad dot net>]

I've go the following function:

SCM graphite_map_tile(SCM tile)
{
   char *name, *icon;
   
   name = gh_scm2newstr(gh_car(tile),  NULL);
   icon = gh_scm2newstr(gh_cadr(tile), NULL);
   
   x_pos = count / x_size;
   y_pos = count % x_size;
   count++;
   
   grid[x_pos][y_pos] = new_object(name, icon, TERRAIN);
   return(SCM_UNSPECIFIED);
}

that gets called repeadedly from a script. The first time it gets called,
everything works just fine, but the second time around, gh_scm2newstr
segfaults. I poked around the guile sources, but wasn't able to determine
why.

Thanks in advance for any help I get.
-Levi