There is very little information to go on here, but there was a bug a while back which caused the control's ItemFromPoint method to throw a null reference exception when there was no item at the specified point; if you are using this method in the release version, that might explain the problem. This bug has since been fixed; if you download the latest version, and the problem persists, you should log an incident with Developer Support so that you can provide the details necessary in order to reproduce the issue.