This generally happens when the network I'm running remote on craps out long enough for the Remote computers SmartLink to loose sync with the radio, and the radio doesn't receive the disconnect command.
Also it helps trouble shooting when you include the SmartSDR version your running because some versions have different little quirks.
YES, When SmartSDR exits normally it sends a disconnect to the radio so other devices or SmartSDR users can access it and not busy the radio out. I am pretty sure this is being worked on by the Guru's at FLEX, to have the radio reset itself after a time of loosing connection. 73's Bret