So I was making some other updates to the plugin, and happened to load my jetpack test page, and noticed some of the images were missing, so I was *finally* able to duplicate your issue. It appears to have been due to a greedy regular expression when removing the link from around an image – instead of removing the opening characters up through the opening <a for that individual image, it was going back to the very first image’s opening <a and removing everything up through there, which included all previous images. Apparently it was randomly greedy, so sometimes it would happen, and sometimes not. I’m working on a fix for this now, so hopefully it will be patched in the next release. Thanks!