BUG #5089: not supported plpsql

The following bug has been logged online:

Bug reference:      5089
Logged by:          Yamashkin Alex
Email address:      default@Smart-soft.ru
PostgreSQL version: 8.4.0.1
Operating system:   windows XP Embeded
Description:        not supported plpsql
Details:

good day.
installing Postgresql 8.4 on Windows XP Embeded available language construct
plpsql requests for functions.
What is our problem and how it can solve?