What would cause a Search Description to work for one user, but not another?

When creating a Sales Order, in the subform the user is able to enter the Item No. or the Item Search Description into the No. field and the system will validate either for the Sales Line. This works for one user, but not for another. They are both setup the same in NAV, as SUPER users and have the same Profile set under User Personalization. What would cause this?
Thanks in advance!