i believe that was reported but bear with me i have no muse to find the topics but i offer one rather repeatable way to get this glitch. be sure Rhinos tools are not set to cascading i have not seen this glitch happening after i have set it to cascading, having recently switched back i started running into it again.
long left click on a command in the left toolbar which you did not use in a while or maybe never because once the glitch happened it does not repeat with this command set anymore. after the hidden commands pop up click on a command voila window glitches into outer space for a moment.