Hi Tom,
Yes I confirm that bug. I don't think the post was specially crafted, I think just the url was changed so that the ids were invalid. I've added checks for that and now it just hides the form if anything looks manipulated.
I've uploaded new files versioned 2-2-3-8-1, just backup mojoPortal.Business.dll and mojoPortal.Web.dll and replace with the new ones.
Thanks,
Joe