hello mark, good question...honestly i don't know..unfortunately google blocked my adsense account and i can't create a new one for my site.
there is no real info why they do this and whats the reason..i got only a standart mail with bla,bla..
from now on i'm never able to use adsense..so i need a workaround to use a other adsense/affilate for central and user blogs!