dirtyb,
After doing some experimenting on my own, it does look like there is a limit to how small the increments can be. Using the graph width from your VI, I created a loop and a control for the X Scale Increment. With 500 as the maximum, I could not get the spacing to be less than 15. With 200 as the maximum, I found the limit to be 6. It appears that the graphs from CVI and LabVIEW display slightly differently when it comes to the scales. Hopefully you can adapt without too much trouble.
JohnM