Three heavy slide rails [A] have been added on top of the registration unit to strengthen the operation of the drawer mechanism. The rails prevent the heavy drawer from tipping forward or shifting from side to side every time the drawer is opened. This greatly improves the stability of the machine, especially for the lighter printer model without the weight of the ADF on top of the machine. These rails must be disconnected and pushed into the machine before some components in the registration unit [B] can be cleaned or serviced.