I have a server that I can cause to die with the following output:
events.js:38
EventEmitter.prototype.emit = function(type) {
The chance of it being a "slightly-too-large chain" seems unlikely.
It's probably a function calling the event that triggered itself.
So if the slowing down of the code is making the infinite recursion to stop. My guess would be that you have a queue and with the slower mode its not getting filled up as fast.
If this doesn't help then I think I need more info. Maybe someone has a catch-all for this though.