In WebdavServlet.doPropfind() method that handles PROPFIND requests there are two resp.sendError() method calls that are not followed by "return;". It should not cause a visible error, but just some wasted work that generates response that is never sent to the client.
Fixed in Tomcat 8 and Tomcat 7 (r1600955, r1600956) and will be in 8.0.9, 7.0.55 onwards. Proposed for Tomcat 6.
Fixed in Tomcat 6 (r1601968), will be in 6.0.42 onwards.