BUG #5800: "corrupted" error messages (encoding problem ?)

The following bug has been logged online:

Bug reference: 5800
Logged by: Carlo Curatolo
Email address: genamiga(at)brutele(dot)be
PostgreSQL version: 9.0.2 64bits
Operating system: Windows 7 64bits
Description: "corrupted" error messages (encoding problem ?)
Details:

On a new PC I install only Windows (French) and PosgreSQL 9.0.2 with default
parameters and without creating any object.

Example of "corrupted" error messages that occurs on several client software
(my own Java program, dbVisualizer, EMS SQL Manager)

[Error Code: 0, SQL State: 42601] ERREUR: erreur de syntaxe � la fin de
l'entr�e

Test 1 : Windows 7 64 bits and PosgreSQL 9.0.2 64 bits

... the problem occurs

Test 2 : Windows 7 64 bits and PosgreSQL 9.0.2 32 bits

... the problem occurs

Test 3 : Windows 7 32 bits and PosgreSQL 9.0.2 32 bits

... NO problem, the error message is correct
[Error Code: 0, SQL State: 42601] ERREUR: erreur de syntaxe à la fin de
l'entrée

This issue occurs only when PostgreSQL 9.0.2 is installed on Windows 7 64
bits...

Is there a solution ?
A workaround ?
Probably this will be fixed in the next release ?

Thanking you in advance.