When I added a region in my custom theme, a subtheme of Seven, the region assignment of my blocks all broke.
I added one region to the .info and page.tpl.php files I believe correctly, and when I cleared my cache, I got the following messages.
The block foo1 was assigned to the invalid region content and has been disabled.
The block foo2 was assigned to the invalid region help and has been disabled.
I was able to copy all the regions from the Seven parent theme to my subtheme .info file and then add my additional region, but is this doesn't seem like the way it was designed. If this is a bug, where should I file it since seven is part of core, and this page doesn't seem appropriate? https://drupal.org/project/seven