Perspective view stops working! Any ideas?

Hello all,

Just wondering If anyone has encountered this annoying problem, I am able turn on perspective view, modify the observer position etc.

Nine times out of ten perspective view stops working during a session! I can toggle in an out of perspective and the model stays in its original state, very frustrating.

I am running 2012 SP 3 Premium 64.

Graphics card NVidia Quadro 4000.

Best regards

Alex.

SolidworksGeneral