Hello Ward,
for a reference I've build a custom ASP-Membership, User-Login = eMail, a custom role- and profile-provider to save Usertemplate and other information in a own datatable with POCO and LinqToSQL.
I hope, I've time to convert this custom Membership-Example to DevForce for Silverlight, in the next two days. When I've done the work, I'll send you the code-sample.
Regards
Dirk