[Zope] ZClass inheritance problem

Hi, I have a main class called JobOfferClass and three child classes InternshipClass, FullTimeJobClass, and TemporalJobClass. When I changed the "view" method in the parent class, the child classes continued using the old view class. I restarted Zope and erased my browser's cache, but it didn't work. So, I just copied the view method in one of the children and it worked. Does the child ZClasses store a copy of the parent class when created or it's a bug? Had somebody else seen this behavior? Thanks in advanced, Josef