Out of no where I all of a sudden started experiencing terrible control over my zooming and navigation around the model. Even after zooming to a selected object when I zoom out I need to roll the wheel atleast 15 times to get the camera to even slightly step back. I did not group anything I did not manually change view settings nothing of that nature it just started happening. When I zoom back in slightly and take my hand off the mouse the model disappears. What is strange is this happened out of no where and a file with hundreds of hours of work into it seems to be helpless now due to this glitch it is almost impossible to work in. Please help.