Another quick thought is to make sure you’re re-initializing the application after changing your handler to make sure that the code you’re looking at in the file matches what’s running. Put “?fwreinit=1” on your URL. There is a handlers auto reload setting for this that you’ll want on in development.
I am definitely sure the current version of the code is running. I’ve set it all to reload in the config, plus given I don’t really trust that sort of thing, I’ve been testing with complete CF restarts too. I am seeing changes to the handler code being reflected as I make them, so am reasonably confident it is not a caching issue.
No manner of code caching is configured on the CF side of things either.