Membership provider method not implemented exception

Problem: I found a code at http://forums.asp.net/t/1148164.aspx to update membership user account. 
While trying to update a membership user account using below code I was getting method not implemented exception

Dim SomeUser As MembershipUser
SomeUser = Membership.GetUser("SomeUserName")
SomeUser.Email = "email address"
Membership.UpdateUser(SomeUser)

Solution: The resolution is given at http://forums.asp.net/t/1834047.aspx/1

MySqlMembershipProvider = (SqlMembershipProvider)Membership.Providers["SQL-MembershipProvider"];
u = MySqlMembershipProvider.GetUser(userId, false);

Update User calls a sql procedure to update database:

http://stackoverflow.com/questions/2721658/membership-updateuser-not-really-updating-the-database