Arrgh!

The problem came back, very annoying. Tried all the obvious things ... no luck.

Finally called Alltel. I had to be persistent, and polite. Finally got through to a fellow geek (geekette?) named Jenny. She was smart, knew how to sling the slang. Was not miffed that the call was regarding an N810. We tried various things, no dice. She then put me on hold, talked to another department, and had them make "a change to the way the data was sent/received to/from my phone". She said it was done by Level 3 and she did not really understand what was changed, that it varied on a case-by-case basis.

But, it worked!

Here is the possibly significant part. When it was failing, ifconfig showed my ip as 166.166.198.210 , which is part of an IP space used by WIRELESSDATASPCO.ORG, and the p-t-p IP was part of the Sprint PCS network (apparently they have some kind of cooperative agreement with Alltel). After she fixed the problem, ifconfig showed me with an ip of 98.132.169.80, p-t-p = 75.116.236.198 . BOTH of those IPs are registered to Alltel!

BTW, it also failed using my phone with a USBcable to my Windows XP laptop, so that proves it had nothing to do with the N810 - I explained that to jenny and she actually took that into consideration while working with me.

So, if you have a problem, insist that it can work, demonstrate that it fails with Windows, and tell them that they need to make the change that results in the IPs being 100% alltel.

Hope this helps someone else,

Steve