Hello Matt,
I would also suggest right-clicking the graph and selecting Properties. A box will appear. Then select the tab for Scales. In the drop down box make sure that you select X axis. Then deselect autoscaling and put your minimum value as 0. This should set the origin to zero.
Try this out. If these suggestions do not work for you, I would like to try and recreate the problem here. If you could simplify your program down to the minimum that still illustrates the problem, I could try and find the problem.
Thanks,
Caroline
National Instruments
Thanks,
Caroline Tipton
Data Management Product Manager
National Instruments