This bug was first reported by Jamie in Feb 2006: http://www.burngreave.net/pipermail/bndfc-web-tech/2006-February/000284.html
Bruno has since confirmed that it also happens on another server.
The symptoms are that sometime internal links are pointed to other sites on the server — the domain name used is the wrong one.
To reproduce this bug all you need is two sites on one server both with a document at, for example, /news/ and if you then create a new document, say /test/ on both sites and add a link component to both pages pointing at /news/ then one of the sites will end up linking to the other.
In addition is seem that there is another bug that prevents pages that have their links mixed yup from being edited, this is the error in the apache logs:
SOFTWARE_ERROR $VAR1 = { 'SCRIPT_NAME' => '', 'MKD__CACHE_DIR' => '/usr/local/mkdoc-sites/linktest.webarchitects.co.uk/cache', 'PATH_INFO' => '/test/.admin.content', 'REQUEST_METHOD' => 'GET', 'HTTP_ACCEPT' => 'text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/p ng,*/*;q=0.5', 'SCRIPT_FILENAME' => '/usr/local/mkdoc-1-6/cgi/mkdoc.cgi', 'SERVER_SOFTWARE' => 'Apache/1.3.34 (Unix) mod_perl/1.29', 'MKD__PLUGIN_LIST' => '/usr/local/mkdoc-1-6/conf/users.conf', 'AUTH_TYPE' => 'Basic', 'QUERY_STRING' => '', 'REMOTE_PORT' => '39905', 'HTTP_USER_AGENT' => 'Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.13) Gecko/20060501 Fedora/1.7.13-1.1 .fc5', 'SERVER_SIGNATURE' => '<ADDRESS>Apache/1.3.34 Server at users.linktest.webarchitects.co.uk Port 8080</ADD RESS> ', 'HTTP_ACCEPT_LANGUAGE' => 'en', 'SITE_DIR' => '/usr/local/mkdoc-sites/linktest.webarchitects.co.uk', 'PERL5LIB' => '/usr/local/mkdoc-1-6', 'PATH' => '/sbin:/usr/sbin:/bin:/usr/bin:/usr/local/mkdoc-1-6/tools:/usr/local/mkdoc-1-6/tools/cron', 'GATEWAY_INTERFACE' => 'CGI-Perl/1.1', 'MKDOC_DIR' => '/usr/local/mkdoc-1-6', 'DOCUMENT_ROOT' => '/usr/local/apache/htdocs', 'PATH_TRANSLATED' => '/usr/local/mkdoc-1-6/cgi/mkdoc.cgi/test/.admin.content', 'SERVER_NAME' => 'users.linktest.webarchitects.co.uk', 'SERVER_ADMIN' => 'chris@webarchitects.co.uk', 'PERL_SEND_HEADER' => 'On', 'HTTP_ACCEPT_ENCODING' => 'gzip,deflate', 'HTTP_X_FORWARDED_SERVER' => 'www.linktest.webarchitects.co.uk', 'USER_DOMAIN' => 'http://users.linktest.webarchitects.co.uk/', 'HTTP_ACCEPT_CHARSET' => 'UTF-8,*', 'REMOTE_USER' => 'chris', 'HTTP_MAX_FORWARDS' => '10', 'SERVER_PORT' => '8080', 'PUBLIC_DOMAIN' => 'http://www.linktest.webarchitects.co.uk/', 'REMOTE_ADDR' => '192.168.1.12',