Problems with tsearch2: ERROR: datumGetSize: Invalid typLen 0

Hi all -

I'm playing with tsearch2. It built and installed normally (this is PG 7.3.2 
on an Alpha running Debian Stable, with the December 18th tsearch2), and 
portions of it work, but, for instance ts_tsvector doesn't:

jal=# select to_tsvector('default', 'Our first string used today first 
string');
ERROR:  datumGetSize: Invalid typLen 0

Archive searches didn't seem to turn anything up... Has anyone seen this
before?

-j

-- 
Jamie Lawrence                                        jal@jal.org
The fact that technology doesn't work is no bar to success in 
the marketplace.  - Philip Greenspun