Stemming not working with tsearch2() function

Anyone know why to_tsvector('sausages') might return "sausages" while
to_tsvector('default','sausages') correctly returns "sausag"?

This is causing me a fairly major headache. I am guessing that the
tsearch2() function used in my trigger is not specifying "default" when
creating the tsvector since the words be put into the vector are not
correctly stemmed (if that is the correct term).

I figure this may be something to do with locale settings, other info:

postgresql version 8.2.4 (upgraded from 8.2.0 by rpm on Fedora Core 6 and
prior to that from a 7.x version although i reinstalled tsearch2)

SELECT * from pg_ts_cfg;
ts_name | prs_name | locale
-----------------+----------+--------------
default_russian | default | ru_RU.KOI8-R
utf8_russian | default | ru_RU.UTF-8
simple | default | en_US.UTF-8
default | default | en_US.UTF-8

lc_collate | en_US.UTF-8
lc_ctype | en_US.UTF-8
lc_messages | en_US.UTF-8
lc_monetary | en_US.UTF-8
lc_numeric | en_US.UTF-8
lc_time | en_US.UTF-8