Hello,
Syncro SVN Client uses its own built-in client. The current version (4.2) is capable of working with any SVN working copy or repository (that is SVN 1.6, SVN 1.5, SVN 1.4). The previous two versions (Syncro SVN Client versions 4.1 and 4.0) are capable of working with SVN 1.5 and SVN 1.4. You can see that in
the list of new features added by each version.
Syncro SVN Client does not convert automatically a working copy in an older format (for example SVN 1.4) to the latest version that is supported (SVN 1.6). It asks you with a confirmation dialog if you want to do this conversion.
Regards,
Sorin