It's a known issue.
If the OCX is being loaded and you click refresh, IE will hang. When you click "Refresh" button, IE will try to unload the OCX and reload it again. For Lookout web client, we cannot control IE's behaviors and the OCX is running inside IE. Whenever you refresh IE page, IE will try to unload the OCX first and it will not care OCX's state. So, the hang happens.
We are trying to find a solution. But right now, we haven't got a fix.
Ryan Shi
National Instruments