imageCLASS LBP674Cdw PF-K1 Tray won't fully close with legal-size paper

[MMC-Printers]

Hi,
We purchased a Color imageCLASS LBP674Cdw with the additional paper tray/feeder PF-K1.  When we put legal size paper in the PF-K1 tray, the door cannot shut.  Using legal size paper makes the tray too long, and the tray door has to remain open (as pictured below).  Am I correct that the tray door will not shut?  I don't want to break anything trying to force the door closed.  

Thanks for your help.