When, on http://www.tamba2.org.uk/wordpress/site-url/ it says:
"NOTE:WordPress 2.0 and 2.0.1 use a cache file. (2.0.2 does not)
You MUST delete this cache or this database change will not appear to have worked.
Delete everything in the /wp-content/cache directory as soon as you make the database change."
Does it really, really mean that? Does that mean delete all the folders and their contents found insisde the /wp-content/cache directory?
Those folders include things like "user logins," "users" and inside those there are more. Does it really mean "delete EVERYTHING?"