WordPress Nginx Media Library = 502 error

No problems at all with wordpress and nginx so far, everything is working just peachy keen except when i try to insert an image into a post from the media library, at which point it just turns up a 502 nginx error. Now I am not getting this error when I access the media library directly, i can view images in the media library, etc etc, only when I try to insert an image into a post via the media library. The apache and nginx error logs aren’t showing anything, so there are really no hints at what is wrong here.

Has anyone else gone through and hopefully resolved this?