Panning with mouse

I have used the PMDG 777 since it first arrived and love it.  One thing I have always appreciated is to be able to pan right around the cockpit with the spacebar/mouse combo.  You can actually see the signed certificates on the back wall of the cockpit.  I do not have EZDOK or FSUIPC.  Just recently my mouse pan seems limited to only 90 degrees - no longer able to see the flight attendants in the jump seats.  I have used the NVidia Inspector to improve my displays, but I don't think it is anything with that (but you wouldn't know) but apart from that I am at a loss to find anything on the internet dealing with this problem.  I am willing to bet there is some box now ticked, or some 1 now a 0, but am running out of ideas.  So, what prevents the mouse from panning more than 90 degrees?  Regards, Phil