Transactional Replication - Add article to existing publication

Hello everyone,

I have transactional replication with a push subscription going from server A to server B, with a distributor sitting in the middle, all SQL Server 2008.  Getting started, I initialized the subscription from a backup instead of letting replication handle it.  It has been running fine for a while now, but today, I added another article to the publication.  This article does already exist on the subscriber (from the 'initialize from backup'), but it wasn't being replicated because the table didn't have a Primary Key when the publication was created, which is now fixed.  So, I issued the sp_addarticle command for this table, then I ran the Snapshot Agent.  When I viewed the details of the Snapshot Agent, there was nothing generated for the table.  I thought that all I had to do was run the Snapshot Agent, then the article would be transferred and kept in sync, but it doesn't seem to be working that way.

The article does show in the sysarticles table in the publication database, but the articleid is not in the MSdistribution_status table in the distribution database.

What am I missing?  Shouldn't the replication process have automatically generated the script for this when the Snapshot Agent was ran, then pushed the article to the subscriber?

Thanks in advance.

Jarret