Hi Dan,
Well, thanks to Michael Zinner I have an answer for you...
The problem you will face is that you will be unable to connect to the MySQL 5 server with the 4.0 client, because the authentication protocol changed between versions. Mike mentioned that the 4.1 client might work, but it would have to be an older one, as version 4.1.3 introduce the changes in the XML format you describe.
So... the choice is to either downgrade back to MySQL 4.0, or change your application to work with the new format. If you are using a standard parsing library, like expat, this shouldn't be too much of an issue. By the way, the reason the XML output format was changed is because the previous format was not XML-compliant -- i.e. it allowed non well-formed entities and attributes.
Cheers,
Jay Pipes
Community Relations Manager, North America, MySQL Inc.
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