This is the entire setup, except for a few things taken out for privacy reasons. Please note that the variables are substituted into the conf files by a preprocessor. I've confirmed that they are substituted correctly.
I'm sorry, my telepathy seems to be failing me. Do you think it would be possible for you to attach a copy of your current pg_hba.conf on the master, as well as the specific entry in the postgresql log with the error about no entry in pg_hba.conf?