This is a known issue that we are actively trying to resolve. Unfortunately, we have been unable to recreate the lost session issue in our local tests here at SmarterTools. Fortunately, there are several individuals that have been gracious enough to do testing on there servers that are exhibiting the lost connection problem.
Please refer to this
thread for more information.
http://portal.smartertools.com/community/a2577/sm-13_2-browser-has-lost-the-session-with-the-server.aspx