With TAC/OG Integration, the simplenews drafts folder at Newsletters->Drafts (/admin/content/newsletters/notsent) does not list correctly:

I seem to have resolved this problem by adding "DISTINCT" to the $action == 'notsent' $query in simplenews_admin_news(). This fixes the problem:

Creating patch for the fix and submitting it to Simplenews issues:

Documented internally here:

• http://clients.brixrealtyinc.com/node/385
• http://www.scbbs.com/node/135/274#comment-274