Our Mitel SX200 running lightware 17 has an issue where when you are terminaled into the PBX and working in the CDE forms it will lock up. If you close out the connection and try to re-terminal in it does not respond. But the switch functions. The last time this happened, once before, i had to hit the reset button? Any ideas what could cause this? Is there another way to fix this other than resetting it by the button.