Enable "logging" in webdav.ini.append.php file, then check in /var/log/webdav.log file what error do you have.
What programm do you use to connect to WebDAV folder? Try with siteaccess name for public view for example plain_user, or news_user as start folder, check your siteaccess names in site.ini.append.php
If you have in webdav.log something like
2005-07-10 09:14:41 : indexdir: /galleries [CS:currentSitePath]
2005-07-10 09:14:41 : no valid site was found.. [CS:currentSitePath]
2005-07-10 09:15:15 : ========================================
Make sure that name of folder for which you want to connect is correct. Also check your re-write rule.