I was very skeptical about this method, but: turned on my nx7300 (t7200 c2d cpu) Leopard 10.5.6 and followed the instructions --> it worked!!!
btw: still to be resolved: iwi3945 and no mic/headphones on ad1981hd.
Correction (2): the method works, except that on my computer it doesn't necessarily hand before the battery dies and there are some hangs (freezes) from which the computer doesn't recover. maybe someone with more knowledge should take a look into why this is. it seems very curious that something as simple as this makes the system stable.
Correction (3): it works sporadically. sometimes it hangs and I can continue once I connect the power cord. sometimes it doesn't. sometimes I end up rebooting a few times before it hangs the proper way...