As Jon says, OpenFTS won't work as is with pgsql-7.2.1. I'm not home (out of town until Monday) either so I can't give you the patch.
However, you need to "gmake install-all-headers" so that all libraries needed by OpenFTS can be compiled. IIRC, the only thing that changed in pgsql-7.2.1 is the server-side include dir. So you'll need to modify that to work with 7.2.1. Search the bboards, I think that this has already been answered.