...the HR department is willing to spend all of that time learning the field and/or working directly with the IT department. They often don't, since they feel you're intruding on 'their' territory (threaten their job).

The advice I give people is that which was given to me during a training course I took awhile back. Whatever they ask for in the job description, parrot back that it is what you have (or otherwise address it) VERBATIM. That will usually get you past the HR drones and into the hands of an upper HR manager that knows more about how things work. Then you can get to the IT people and/or interview process.