Upon intial request from the IIS frontend, the authorization block has null credentials,an empty cookie and there is no username/password in the session object. No auth information or cookies are forwarded to AutoVue/DMS it seems(I have set the proper applet properties to preserve cookies). Therefore the user is defaulted to "anonymous" and the DMSSessionImpl is connected as "anonymous".
I need more information for your question. Are you using the same frmApplet.jsp coming with the sample integration of filesys? This demo project supposes the username and password are stored in the session using setAttribute(); if no user name and password available in the session, the "anonymous" user will be used instead. Usually for your integration, you are not supposed to store password in the session or use default username for DMS (it is not safe). Please check the JSP.