OG audience not selected when adding event

This is an old, remanent issue

http://drupal.org/node/704636
http://drupal.org/node/875358

The issue is well explained in the above

* The Add+ link takes one here: /node/add/date?destination=calendar/8/2010-08 which claims to add a date node type for OG 8 but it doesn't have node/8 (OG) checked as an audience. But this node/add/date?gids[]=4 does actually add a calendar event for node/4, but how do I make Add+ do this?