As suggested I posted my question about the Mod in the appropriate thread, but 2 weeks later still no reply...
After upgrading to 2.0.12 the Post and PM Inline Attachments Mod doesn't behave as it should. The attachment do not auto thumb anymore, nor inline, nor under the post
you would need to post in the mods support topic and wait for the author to reply.
Yeah, I know where to post it and already did a while back, so I'll just wait longer...