[AccessD] Text field not editable, weird issue

I'm experiencing something weird on a user's computer.

New user (to my database app), new screen (built specifically for her).

Her screen works great on my computer whether I'm logged in to the ADP as
me or as her.

On her computer, it seems to be stuck in a previous text box After Update
event.

The first text box on the screen is where she enters the PO#.

Here is the code in the after update event:

Private Sub txtTranNo_AfterUpdate()
 DoCmd.SetWarnings False
   Me.lstModelSumm.RowSource = "EXEC dbo.stpSelectTempMach 0"
 DoCmd.SetWarnings True
 Me.lstPoResults.RowSource = "EXEC dbo.stpPurchasedMachinesByPO '" &
Me.txtTranNo & "'"
 If Nz(lstPoResults.Column(0, 1), "") <> "" Then
    Me.lstPoResults.Selected(1) = True
    Call PopulateFields
 Else
    Call ClearEntryFields
 End If

End Sub

I put a break point on the very first line and stepped through every line.

On my computer I can click on any entry field and enter data or combo box
and select a row.

I can do same either logged in as her or myself on my box.

On her computer (logged in as her or myself), I can step through every
line, but If I click on any other control,
it behaves as if those controls are locked and if the break point still
exists the first line of
txtTranNo_AfterUpdate() is highlighted yellow.

It is like we are stuck in the after update event.

Any ideas?