Intel,Altiris Group

When a ticket get reassigned in SD7.0, sometimes in the Assigned to inthe ticket it is blank. Has anyone seenthis before? When this happens our Task Assigned to Users Report gets very large because the assigned to is blank. We have to manually reassign the tickets. Any ideas would be great. Thank  you.

Yes I have seen this but I don't know why this happens or how to solve it: In the history you can see when the task was assigned and to whom, but it is blank or does not show all the assignments in the Assiggned to section.