Subversion is Alpha software, and there are plenty of known bugs (see the Tasks page for a detailed list). Below are some of the problems most likely to annoy new users.
If you interrupt a checkout in progress, you'll need to toss the working copy and start over.
See Issue #730 for more details.
Charset encoding (i18n) conversion is not yet supported on Win32, due to problems with our portability libraries, apr and apr-util. There is no issue associated with this, but it is being actively worked on and should be fixed soon. Meanwhile, stick with 7-bit ascii on Windows.
If Subversion cannot convert log data to your local charset encoding, it will (currently) just show "[unconvertible data]" for the entire unconverted log message. This is lossier than necessary. There are even some revisions in the Subversion repository itself that exhibit this behavior when the client locale is ISO-8859-1 (Latin-1).
See Issue #807 for more details.
If an svn client is directly accessing a repository via a file:/// url and is interrupted, or crashes, (or if httpd crashes), the repository is likely to be left in a 'wedged' state. You'll need to run Berkeley DB's 'db_recover -ve -h repos/db' to unwedge the repository. Make sure you shut down httpd before doing this.
See Issue #739 for more details.