since some time I don't add people, so I don't know if with
latest Skype 8.59 it begann a bit buggy...
Anyway, I am afraid that when it gives only one result there's
only a button which lets you invite your friends to use Skype, so
chances are your friend did not make a Skype account using only
his/her cellphone number, and/or he did not put the number in the
profile.
