I also found this site:

http://www.clarkwire.com/PinOutXLRBalanced.htm

Which says specifically, "Some manufacturers, especially in vintage equipment, do not follow this standard and instead reverse the polarity of pin 2 and 3."

But by glancing at the Sunfire manual, it doesn't appear as if the polarity is reversed. Can someone verify that for me? It's online here:

http://www.sunfire.com/manuals/Cinema%20...er%20Manual.pdf