Hi dvulyak,
Thank you for using the forum.
You may find the following instructions for different paper size setups, helpful as a solution for your question.
Solution : Load Paper or Specialty Media in the Paper Tray
http://www.support.xerox.com/support/3250/support/en_US.html?objGUID=1046
If that does not help then you may consider using the following link Fast Track to the Expert