BUG #2071: ERROR: invalid multibyte character for locale

The following bug has been logged online:

Bug reference: 2071
Logged by: Prakash Nair
Email address: prakashblr(at)hotmail(dot)com
PostgreSQL version: 8.0.4
Operating system: RHES
Description: ERROR: invalid multibyte character for locale
Details:

Hello,

Got the error in postgres console when we do a lower() or upper().

Postgres console gives following error,

ERROR: invalid multibyte character for locale
HINT: The server's LC_CTYPE locale is probably incompatible with the
database encoding.

Can any one please help me, I need to use Unicode encoding for my database.
(Not able to upgrade to postgres 8.10. as I was getting someother issues
when I try to restore database)

Looks forward for anyone's fast reply.

Thanks,
Prakash