I sent him an invitation and now he can see my board but I can't see him as a member. Also, I can't assign any task to him. Am I doing something wrong?
If you can't see him as a member I doubt you will be able to assign a task to him. Please clarify.– phwdJan 25, 2012 at 5:27
Invited users can see the board, but until they actually accept, they are not a member of the board (can't be added to cards, move cards, etc.). The user probably hasn't accept the invitation yet.