LBP632Cdw only prints labels from multi purpose tray

[therealex]

I'm trying to print postcards from a sheet of 4.  I'm using the Avery 3380 template.  Although both the Word printer dialog and the printer are set to use Tray 1, it insists I use the MPT.  I even tried copying and pasting it to a default Word document, but no dice.  Is it because the margins are set to basically 0" all the way around, or is there some arcane method of forcing it pick up from Tray 1?  Blood sacrifices will be considered as a last resort (obviously not MY blood). 
Thank you.

[Hector]

Hello,

We would be happy to assist, but we would need some additional information to assist further. You can reply to this message with the information below and we can provide some troubleshooting steps or suggestions. For a more immediate resolution I would suggest contacting support over the phone at 1-800-652-2666. Our agents would be happy to assist.

1. What size is the sheet of paper that the 4x6 post cards are on?

2. What version of the Mac or Windows operating system are you using on your computer?