Since I don't know what you mean by "switching forums" my answer to your question is "no", we didn't switch forums.
What we did do was upgrade to a newer version of Photopost.
It appears that now anyone who uploads a photo to a category is automatically SUBSCRIBED to that category and begin receiving emails about other uploads to that category. They don't want those emails, and the LINK in the email that says "click me to unsubscribe" isn't unsubscribing them.
I want to not have members automatically subscribed to a category when they upload a photo. Where can I turn this OFF?