> So the new version is not backwards compatible? Sounds like a Microsoft product...
SVN is backward compatible like most software: newer versions can work with older version's data. With current SVN you can create v3 repos but the default is v4 and the main problem is that Designer does NOT give a meaningful error message in case it comes across a v4 repo.
Repo version 4 was introduced with Subversion 1.6 in march 2009, btw, so this is not a "new" version at all.