I have also had some problems being "not authorized", but for seeing a discussion. Wonder if they are working on another software update again? Where is the software vendor's testing department, that is maintaining this site? It kind of seems like poor testing before they keep making updates.
I am guessing that it may be a problem with copyrights if the source of your photo is not you or a friend but from the web. As a work around you can download your photo to a program like Picasa (free download from Google) and save it there. I havefound that my larger photos, when rejected are accepted if they've been through the Picasa store and save regimen.
Have you tried it lately?
Am trying to comment on various properties that I have stayed at and offer "Travel tips" for future travelers.
Have not been able to post pictures for two days. For the most part they involve, or show Marriott properties, so I don't know why they are not being loaded on the posts.