Pretty simple, pretty serious: 1.5.x client cannot talk to 1.4.x svnserve.
$ svn ls svn://localhost/testrepo
svn: Can't connect to host 'localhost': connection refused
$
For details, see this message and the thread leading up to it:
http://subversion.tigris.org/servlets/ReadMsg?list=dev&msgNo=136247
From: Stefan Küng <tortoisesvn@gmail.com>
To: dev@subversion.tigris.org
CC: Mark Phippard <markphip@gmail.com>
Subject: Re: 1.5 client can't connect to 1.4 svnserve
Date: Fri, 21 Mar 2008 17:49:06 +0100
Message-ID: <47E3E702.9040808@gmail.com>
Assigning to self.