Are you perhaps talking about a bug in the control (logged and described here
) - the line is snapped to a point that was actually removed from the datapointinfos? If this is the case, you can vote for the bug and track its status. Let us know if this is what you mean and if you have any other questions.
Check out Telerik Analytics, the service which allows developers to discover app usage patterns, analyze user data, log exceptions, solve problems and profile application performance at run time. Watch the videos
and start improving your app based on facts, not hunches.