I've just followed Spammish's train tutorial and made a working train (and, with some entity experimentation, added working gates :thumbup, but there's a problem: when the train reaches the path_track which contains the OnPass output to stop the train sound, it doesn't stop. It seems that I can't even make it stop in-game using the ent_fire console command. :\ I've double-checked all my entities, and it's clear that the ambient_generic producing the sound is hooked up to receive the StopSound command from the path_track, but for some reason it still doesn't. What should I do to make it stop? I can upload my .VMF if needed, but it's virtually identical to the one built by Spammish in the linked thread, except for the addition of gates, which I know had nothing to do with the problem as it was there before the gates were added.