BUG #4148: tsearch related issue

The following bug has been logged online:

Bug reference:      4148
Logged by:
Email address:      dksingh.engineer@gmail.com
PostgreSQL version: 8.3
Operating system:   windows xp
Description:        tsearch related issue
Details:

Hi,
  I'm using tsearch in my application.
for query SELECT to_tsvector('surprise') it's showing result as 'surpris':1
but when I try to search this word its returning false.

SELECT to_tsvector('surprise') @@ to_tsquery('surpris');