Using the corded iPhone headset with VOIP on a MacBook

[bryanus]

The difference is that you're looking at EARLY-2009 and mine was a MID-2009. It was dropped in the MID-2009 for whatever reason, then brought back I guess in later models.

That is really odd, because the specs for the uMBP early 2009 (both 15" and 17" listed) DO show support for the iPhone headset:

http://support.apple.com/kb/SP503

The mystery deepens: