tsearch2 issue

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 as it seems the tsearch2()
function used by triggers is not specifying "default" which means
many words that are index are then subsequently not found.

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)

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