There is most likely a problem with the mappings to the .svc and .xamlx extensions in IIS. Can you please make sure you have everything set up as per the instructions on this page
of our Installation and Administration guide? If this does not fix the problem, could you please record a trace of the web service exceptions that occur while browsing the problematic content on your site (you can refer to this KB article
for more information on how to do this). Also please make sure that in your mappings for .svc and .xamlx extensions in IIS you do not have restrictions over the verbs. If you have WebDAV module enabled in IIS you will have to disable if for your Sitefinity website as WebDAV module forbits PUT verb.
the Telerik team