I recently spent about 2 hours trying to get my Distribution Provisioning Profile to show up. I followed the instructions and did everything, but still it would not show up.
Then I came across this thread: http://www.v2ex.com/2008/10/22/distribution-provisioning-profile-not-showing-up/
The first suggestion was to create a new project. I created a new project and my Distribution Provisioning profile appeared in it. Then I went back to my main project and it appeared there too. Problem solved!