I need someone to help me understand cursor behavior with in a form.

I have a form that runs SPT on load event. I have a field that holds a record seq number. If I scroll through the records to a record where this field is empty, type in a value, move to next record, click in the text box to add a value, at this time the value I typed in before appears in the text box. Since this text box is based on a field in my SPT cursor, I don't want some automatic value populating this box.

Why is this acting like this?