In part 2 of this series, I promised to let you know how I'd been doing with my hotfix solution to this problem.
[History: After increasing my laptop's memory past 1GB, in Windows XP SP2, I find that the laptop will occasionally refuse to hibernate, with the cryptic message "Insufficient System Resources to Complete API". A Microsoft Knowledge Base article makes it clear that this is a known bug, and offers a hotfix. After going through the simple procedure of getting the hotfix sent to me, it's now even simpler, because the hotfix is available to anyone to download, without having to call Microsoft.]
I'm happy to say that this has been going really well. My laptop, with 1.5GB of memory, now hibernates wonderfully well all the time, and I no longer fear that I will be pulling a red-hot laptop out of my bag after I've closed the lid in a hurry.
I do still hit the problem that if I press the power button, then close the lid, it hibernates once, and then a second time immediately after I turn it back on. Not a big problem – certainly not as big a problem as running the laptop's processor and fans at full tilt inside a sealed laptop bag because it didn't hibernate.
Lessons for those watching: