Mentat: that's an interesting end to the story, but so many other posts were from owners who (I hope!) did NOT have a steering pump leak to explain it, so I wonder if there is another cause?
I had the same experience this past May (BEFORE I downgraded my software to 320, if that means anything): as soon as I ran out of charge, the a/c blew hot air the rest of the ride home (30 minutes; not momentary at all).
Just one more reason to avoid running out of charge while driving, like Karma373 said.
Karma #328: Shadow on Monsoon Tri-tone