(Previously, on CKL's HotSheet... "Languishing Laptop." And now, the continuation!)
I picked up my repaired laptop from Northwest Computer Support yesterday afternoon. That's their work order number sticker on the corner of the lid. They replaced the main board under warranty, so I didn't have to pay anything, and the good news is that it now boots up properly and works as before. The bad news is that coming back from standy/hibernate still kills the wireless networking.
After updating my NIC drivers to the latest from the manufacturer's web site, I now have yet another icon in my XP system tray (Intel's PROSet/Wireless WiFi Connection Utility, which so far seems to be playing nicely with Lenovo's Access Connections--knock on wood), but still no solution to the problem.
I'm very happy with Northwest Computer Support's service. They called me as soon as they started the repair, and were done with it just two days later. I'm so happy, in fact, that I'm taking my laptop back in on Monday so they can investigate this standby/hibernate issue.
Having done my own research on the web and found many other reports of the same problem, I'm not optimistic that they'll be able to fix it. But I might as well get my money's worth out of this warranty before it expires on the 30th.