Well, the copy of the Stop Forum Spam modification in v7.5.8 Refresh (the current codebase) tests IP's on registration as well which in your example shows the users listed so it should trigger them as well on registration. There are also modifications at UBBDev for Stop Forum Spam for both your version and the latest version to extend where it tests for users (in fact the change in 7.5.7 is also at UBBDev that was added to 7.5.8 to detect registration ip's).
