MySQL officially announced release 5.0.22 today (the release notes in the manual were not yet updated to reflect this at the time of writing, they might be when you read this). It's a security fix release only, based on the previous 5.0.21 release. So be careful if you're currently running a preview release of what was tagged 5.0.22 before, this has now become 5.0.23. So you will lose some of the functionality or bug fixes by switching from a 5.0.22 preview to the final 5.0.22 release (it's not an update but sort of a crossdate).
The right way of handling the situation therefore is:
- If you're currently running 5.0.21: Update to 5.0.22 to get the security fix for the SQL-injection hole in the multibyte encoding processing.
- If you're currently running a 5.0.22 preview …