Starting with tomcat 6.0.33 the tomcat behavior for request.getPathInfo() has changed. It seems that the servlet specs require this method to return the jsessionid part of the request path as well. Older versions of tomcat kindly removed this bit.

the info.magnolia.module.admininterface.PageMVCServlet#getHandler method is not taking this into account. It should test for and strip from the path the jsessionid.

In our setup this omission collides with the curious fact that the login filter now creates a redirect url that contains a jsessionid bit that is appended with '.[hostname]', as in: http://redactie.3voor12.vpro.nl/.magnolia/pages/adminCentral.html;jsessionid=06CABB93C2E6BED8A46434E883CD298C.vpro6a

This breaks the page name resolving code. We still don't know why this url is create in this way. We will log it when we do.