The after update of the location combo should look like:
Code:
Private Sub Location_AfterUpdate()
Dim strSQL As String
strSQL = "UPDATE [TBL_Records] SET [TBL_Records].[Record_Location] = '" & Me.Location & "' WHERE [TBL_Records].[Box_No] = '" & Me.Box_No & "' AND [TBL_Records].[Record_Location] = '" & Me.Location.OldValue & "'"
DoCmd.RunSQL strSQL
DoCmd.RunCommand acCmdSaveRecord
Me.SUBFRM_Records.Requery
End Sub