Printing fix.

If there is an exception, (we assume it's because of the time Slider being somehow out of whack -- TODO: add a check on the exception to make sure). If error, reset the timeSlider to 0,1, and retry the print.

If the user had already changed the value of the time slider, the function should work without this extra voo-doo. (And this code shouldn't affect the user's selection...we hope)