I've been waiting a long time to be able to post photos also. One suggestion you can try in the mean time is maybe upload the image to imgur or something similar and just include a link in your post here when asking the question.
The spammers would post something clean and then come back later to edit in the spam on their own posts. The only solution at the time was to remove editing to all but the admins.
I believe something like that has been suggested already. It may depend if the forum software allows that. I'm not familiar with how this software works behind the scenes so I can't say for sure.