Dead MacBook Air power adapter resuscitated - an SMC firmware problem?

I'd like to pass on the weirdest hardware glitch I've seen in years. Details are on my blog [1]. Special thanks to Dan S for the fix. I suspect this is fundamentally a MacBook air SMC/PMU glitch that will require a firmware update to fix.

This morning my 6 week old 11" MacBook Air was not charging. The 45W power adapter diode was not glowing.

I cleaned the contacts and checked all pins were moving and extended. I shut down and restarted. Nothing.

At work a friend's adapter charged, mine still did nothing.

Then I let my Air charge for about 40 minutes with his adapter. Based on Dan's advice [1] I tried mine again. This time it works. My Air is charging.

I assume the $80 ! Mac adapter does not have its own OS and that it does not have emergent behaviors.

So I assume this is a glitch with the MacBook Air's PMU. Perhaps a PMU/SMC reset would have worked [2] if I'd not had access to an adapter. I'll do an SMC reset once my Air is fully recharged.

Shut down the computer.

Plug in the MagSafe power adapter to a power source, connecting it to the Mac if its not already connected.

On the built-in keyboard, press the (left side) Shift-Control-Option keys and the power button at the same time.

Release all the keys and the power button at the same time.

Press the power button to turn on the computer.

Note: The LED on the MagSafe power adapter may change states or temporarily turn off when you reset the SMC.

[1] http://tech.kateva.org/2011/10/apple-portables-and-power-adapters.html

[2] http://support.apple.com/kb/ht3964