Seeing as Octane666 doesnt play wow any more and hasnt updated spammenot for 3.1 i thought i would give it a quick look over.
now its not a perfect fix but if you change the ChatFrameFilter function in the core.lua file at line 180 to:
function SpamMeNot.ChatFrameFilter(self, event, ...)
return SpamMeNot.filter:FilterEvent(event, ...), ...
It should stop it filtering everything. sadly (!) i havent found any gold sellers so i cant tell if it still blocks them yet, bit it seems ok so far.