Organic Groups Views contextual filter is not working
I had a similar issue and it took me hours to finally find this solution:
http://drupaleasy.com/blogs/ultimike/2013/05/sneaky-previously-undocumented-views-feature

I know it's for overriding the title, but it worked for me when I wanted to display a certain content type in a view for a specific group based on what page I was on. I fiddled for quite some time with relationships and different combos. But, all you need is the contextual filter: OG Membership: Group ID with a default value provided (current OG group from context) and specify validation criteria (OG GrouP). 

Hope this helps!