Using latest version of both the plugin as well as wp, and noticed that the plugin instapress conflicts with the wp-o-matic plugin. I got wp-o-matic to work perfectly and was about to solve the issue of the automatic posts to post to the "html" editor instead of the "visual" side, and noticed that the instagram images dissapeared...deactivated wp-o-matic and the images came back. So if there is a fix that can be done fairly easily then I will continue to use it. If not ill have to move on :( . Let me know what you come up with!
Love the plugin though, didn't want to come off as a jerk and bash your work.