At the moment, the way IP caches off-line images leads to compromising other website / server restrictions when it comes to hot-linking.
The two images here DO HAVE "NO" hot-linking at the server and functions normally with other forum / website software.
For example if you "Click" the images below - you get what you should only be seeing when this post / thread was submitted.
Whether you like it or not - This is serious, and in the current format that the restricted images are being handled could raise some serious objections as to the integrity of IP.
Unfortunately I've had to revert back to squashing hot-link prevention for now for other reasons, but the fact of the matter is IP should not cache the "Preview Image" - rather it should cache the off-line "linked" image when the post / thread is submitted.