I think what is happening is that order of what is happening is that
1. Line 9 from above opens the form
2. The form's OnLoad event triggers and sets the control to the value you are wanting
3. Line 15 runs moving the form to the new record.
Just to be sure, which form is getting moved to a new record? You can also watch to see if this is in fact what is happening by putting a
stop between lines 1 & 2 in your above code and then using F8 to step through the code and watch when values are getting changed.
You can put the code to transfer the value in you above code, but you would have to switch which control is getting the full reference. Like this:
- Forms!GeneralTabPullTest!LotNumber = Me.LotNumber