Sorry I was on business travel and unable to respond until now.  I appreciate very much the hotfix.  What number hotfix will it be, and when will it be out?  This problem still occurs consistently for me so it is absolutely necessary to have this fix, as it is a serious problem.  As soon as the hotfix is out I will update you on whether it worked or not. 

I can send you the little sample project I made, but it only occurs one in 5 times, but it really depends on PC specs probably, etc.  I can't send the full software unfortunately. 

I was still unable to reproduce the problem with your code. I tried it both as is and in form load. Regardless, I have added null reference checks to both Scroll and Scale methods of the axis. The changes should be available in the next hotfix, although I cannot fully guarantee it will solve the problem. In the meantime, it would be best if you could submit a stand alone project to developer support for testing. This way they can log a bug for you.

The adding to trhe series is NOT done in my real UserControl in the constructor.  It is instead done AFTER the form has loaded. The problem exists in both places, regardless of whether done in form load or not.  There's a null reference somewhere due to timing?  Can you recreate it with my code there?  Move into to form load, it'll do the same thing.  Thanks.

You should move all the code from the form's constructor into the form's load event. The constructor should only be used to initialize properties and variables. I bet it'll work fine from the load event.