Any chance to have Terminals supporting Network Level Authentication? ...or to write the exception into the log? :-)
The reason I suspected this is a NLA issue, was because I had the same issue and have been playing around with the source (one of the benefits of an open-source project)
I have submitted a patch which the developers can evaluate.
Although I was displaying an error message on connection failures rather than writing an exception to the log file. This has to side-effect of displaying an error if your rdp connection drops unexpectedly, but I have been playing about with this for about
a fortnight and don't find this intrusive.
I have only one server that requires NLA, which means it is not an extensive test, so all I can say is that it works on my machine.