Claire,
Updating the Activdriver should help with the interaction of the pen on the ActivBoard. If you have admin privileges, you should be able to update the driver. To do this: Disconnect all Promethean USB devices from the computer.
On a Windows computer, remove/ uninstall the ActivDriver from Add/Remove Programs or from Programs/Uninstall depending on the version of Windows you are using.
On a Mac, go to Applications > Promethean > ActivDriver > Uninstall
Restart the computer and Save/Run/Install the latest driver version for your operating system located at the link below.
www.prometheanplanet.com/.../SearchProductFiles.aspx
Once the driver is installed, reconnect all Promethean USB devices to your computer and calibrate the board.
Hope this helps!