When the bulk change for setting parents was done it must have been done carefully in trunk and thrown over to Release branch because in trunk they are OK and in Release branch we have many topics that have WikiUsers as parent. Problem is that WikiUsers is in Main web and not System web.
And it makes little sense to have WikiUsers as parent to many of these anyway.
I am removing these broken parents - Release branch only
-- KennethLavrsen - 03 Jan 2010