Editing own content for content type giving me access denied
The "input format" on the body field might be set to one that you don't have access to, example  "Full HTML",  "PHP", etc.

Check that you (your role) has that access. Look here: "admin/settings/filters"

If you don't have access to the "input format" used on the body field then you can't edit that content. 

I recently ran in to something close to this, I was surprised to find this as the solution. Hope this works for you.