CREATE DATABASE cannot be executed from a function or multi-command string

I get the above error message when creating a database in pgAdmin now:

CREATE DATABASE demo
WITH ENCODING='SQL_ASCII'
TABLESPACE=pg_default;
COMMENT ON DATABASE demo IS 'This is the demo database';
GRANT ALL ON DATABASE demo TO public;
ALTER DATABASE demo SET search_path=demo;

I understand what the message is telling me to do, but what is the
reason for this change, and is it really *required*? The way pgAdmin is
designed, a change to accomodate firing everything off in seperate
queries would be a significant one which would most likely require us to
effectively restart our whole beta process and may well mean we don't
have a release ready for 8.3 in fact :-(

The only other option I have at the moment is to force the user to do
the above operation in two stages which I'm sure you'll agree is not
very friendly.

Regards, Dave.