I have been having continuing issues with some drawing files which I created, when invoking the NW Isometric view ONLY, in model space, on semi simple 3d models (approx. 7-10mb size). Acad simply goes into a lockup mode, and elicites a "not responding" situation, requiring a 3 finger salute to kill the application. This was occurring originally on a machine running windows XP, but I recently switched to a newer machine running Windoz 7, and did not have issues....until today.... I assume it's something resident within the drawing file, which I created, but did bring in some objects from older models. Maybe there was issue with some part...just curious if this has been reported, and what was the cause /cure. t.i.a.