If you are searching based on date assigned status, make sure that the assigned status is only assigned once. If it appears more than once, and both dates fit your search criteria, then it will be listed twice. I deal with this issue on a routine basis in my own company.

I would add code to prevent this, but how can the report know which date is the correct one when it appears twice? Further, what if only one date appears on the report, then you run it at a later date to pick up the second? Now you've got the order recorded twice on your books, not good.