Not sure if I can be of much help since I just started some work (and about to wrap it up, since auth is not working) with Iirf as well. But that much being said, the log file was another eye opener. Iirf will create log files for the processes and attaches
the process number (I believe of the worker processes) to the log file. So if you have a setting
it will actually create
log files and so forth.
Lesson learned: You will have to set directory write permission for your user that is actually running IIS.
Makes sense? - Hope that helps!