i have been building a model in teamwork space for a few months now, and all of a sudden, i have lost my ability to navigate in perspective view in 3d space. nothing shows up when i zoom extents. parallel projections work just fine. when i manually try to reconfigure the 3d model projection settings with exclusive access, and i manually enter new values for any of the fields (distance is stuck at 3 3/8") and i close and then reopen the setttings box nothing has updated. its as though the perspective settings are locked. i can't figure this out.