Christina,
The Dual Pen feature was designed to work with a teacher and student pen. The teacher pen will only interact with the teacher toolbox and the student pen will only interact with the student toolbox. To use the dual pen function you will need an upgrade called "ActivArena" which includes a firmware upgrade for the board to detect the teacher and student pens at the same time and the teacher and student pens. This upgrade is available for purchase through any Promethean Reseller. (case# 241020)
Thanks!