By default, the Graphene theme on Wordpress doesn't do comments on Status or Media posts.
I'm not entirely sure why that is, and it took a little effort to get it working for me.

In the end, it came down to a single line of text.

Go to appearance/editor, and open the loop.php file.

In there, you want to add the line...




Within the upper loop-based section of code, as in the following image.



No guarantees this will work on all setups. I'm currently using Disqus to handle my comments, so it might just be magically working for me, but I figured it might be handy for others.

Good luck!