During the past couple of days our Tomcat installation, including the Xamin and login service web services, has not been very stable. This may be due to some error in the Xamin or login service web service but regardless of the origin, it is causing significant problems for Xamin queries. We have reset HEASARC cone and batch queries to use Browse until we identify and rectify the problem. We apologize for the inconvenience to users.
Update: [12/3] We have gone back to using Xamin for Cone and Batch queries.