Simply had to share this workaround to maven release:prepare not working with subversion 1.5, especially after it’s taken me most of the day before a big release to discover it. In fact I didn’t discover it I asked a colleague (thanks Ian).
After mvn release:prepare fails with a message about a tag file already existing, run svn up . The re-run mvn release:prepare and voila!
I thought I was going mad :(