In my current project I had to add claims to a sharepoint group to controll access to sites and pages. In this project we have built a custom claims provider and one of our own claims had to go in to this group.
Unfortunately I discovered a bug, in my opinion, in the people picker.
Our custom claim provider produces two claims with the same name(value) but with different claim types. When trying to add one of these claims to the group, I get an exception saying some something like:
No such user, group or duplicate found
What I had to do to solve this problem was to add a prefix to our claims in the claim provider.
This solution seems to work quite well.
Has some one else ran into this problem and have another solution?