Problem with Skaven file to report!!

[michael430]

Whenever I take more than one "warpstone token" with a skaven wizard it tell me that, "One or more magic items has been taken more than once." In the skaven book it states that, " In a similair way to scrolls, all skaven wizards in the army can buy as many warpstone tokens as they can afford within the limits of the points they can spend on magic items. Buying one or more tokens does not count as taking an Arcae item." Army builder says my list is invalid if I try to buy more then one token. Would someone please fix this??? Thanks.