Error in ALTER DATABASE command

In Postgresql 8.2.9 on Windows, you cannot rename a database if the name
contains mixed case.

To replicate:
1) Open the pgadmin tool.
2) Create a database named "MixedCase" (using the UI, not using a query
window or using PSQL)
3) Open a query window, or use PSQL to issue the following command
ALTER DATABASE MixedCase RENAME TO anything_else;
PostgreSQL will respond with:
ERROR: database "mixedcase" does not exist
SQL state: 3D000

This does not happen if you create the database using a manual query in
pgadmin, or if you use psql. Both of those tools will create the
database as "mixedcase" instead of "MixedCase"

I am using:
"PostgreSQL 8.2.9 on i686-pc-mingw32, compiled by GCC gcc.exe (GCC)
3.4.2 (mingw-special)"

I guess for now, I have to dump and reload my database. :(

Postgresql seems to force many things to lower case. Is it a bug that
the admin tool lets you create a database with mixed case names? Or is
it a bug that you cannot rename them thereafter?