Apparently StopForumSpam.com has a policy where they only accept submissions if the user actually spammed; they do not allow "guilt-by-association". SFS checks IP address, usernames and email address.
On my forum, where the heuristics are set to "medium", for someone to rejected, it has to match two of the three resources. If someone is rejected, it then submits the third resource into the system. SFS considers the submission of this third resource to be "guilt-by-association", since this third resource has not technically submitted any spam.
So this update is to comply with StopForumSpam.com policy and remove automatic re-submission.