I am seeing occasional UUID changes on this repository, which svn-1.5.2 at least doesn't like. I'm not sure under what conditions an SVN repo will change its uuid, but you can run "svnadmin setuuid" to reset it back.
That would be because I sometimes run my script which makes a new conversion from scratch based on the CVS repository. Thanks for the tip about setuuid, I'll integrate it into the script.