Hi Tom,
I still think a brighter pen may help, do you have any suggestions of pre-made pens that are significantly better than others.
I’m afraid I can’t help you with that since I’m not actually using the app in a classroom. As far as I know, there is a certain type of very bright infrared LED that most (if not all) IR pen vendors use; please take a look at the wiimoteproject.com forums for more information.