What class does the Lurk use? Not familiar with it.
Usually it is defined by sClass.cHelpWiz fro the wizard. I was just helping out Eldamir with a similar issue over in:
http://forums.wolflair.com/showthread.php?t=56594
In that case, he needed to change the base spell list to sorcerer so: perform focus.assign[sClass.cHelpSor] did it for him as a Spellthief.