Hello again, I'm back with a updated summary of my n810 experience to date:

I purchased my brand new unit on December 6, 2007, and immediately had trouble turning it on after the initial battery charge.

Unable to find a complete software / finesse solution to the issue, but loving the n810 so much that I didn't want to give it up even for a day, I eventually and reluctantly decided to send it in to Nokia for warranty repair. Their turnaround time was spectactular by anyone's standards: they received the unit on January 10th, performed their repair tasks, and then mailed it back to me on January 11th.

Now that I have the "repaired" unit back in my possession, I will tell you all something that will make your hearts sink. I STILL CAN'T TURN MY TABLET BACK ON WHENEVER I WANT. They sent back the same unit, with notes that were not as detailed as I had expected. "Fault Information: NO PWR UP/DOWN / INTERMITTEN" and "Repair/Parts Used: Full Software Upgrade & Phone Reset"

The fast turnaround time was great, but I would rather they had kept it for an extra day or two to actually test it and make sure it worked properly before sending it back.

Just a couple of days ago someone posted a brilliant idea:

xterm
sudo gainroot
shutdown -r now

Restarting my tablet is now a no-risk gamble. Thank you, bunanson.

Unfortunately, as expected (but worth a try) . . .

shutdown -h now

did not change anything, my unit is now off and cannot be turned on. I have plugged it into the AC adapter and expect it to display the battery indicator within an hour or so, and then I'll be able to power up again.............................. ok, it just came back on. That time it took about nine minutes. Not so bad for a completely unpredictable issue, eh?

Since I've had this thing back from "repair" it has recovered in less than an hour each of the four times I have tested it. All I have done to get it working again is:

Sigh
Plug it into the power adapter
Walk away

When I come back to check on it, the battery charge indicator is displayed on the screen . . . indicating that the unit is alive again and ready to be powered up.

I ordered another n810 (directly from Nokia this time) yesterday, and once I have it I will send this faulty unit back to the repair center again.