Our good buddies at IDG News Service report that the failure of a DNS (domain name system) server at Comcast caused problems for some Web surfers in the northeast section of the U.S. today, making several Web sites, including Google, inaccessible.

The server failure caused connectivity problems for a “few hours,” said Jeanne Russo, a Comcast spokeswoman. By late Tuesday, the broadband provider had rerouted traffic to other servers, she said.

An undetermined number of Google users who subscribe to Comcast’s broadband service “experienced problems accessing Google and other services for a short period of time,” a Google spokesman told IDG News via e-mail.

“Google engineers helped troubleshoot the problem and provided diagnostic information to the ISP. We believe the issue has since been resolved by the ISP,” the spokesman wrote.

The server was knocked offline because of a hardware failure, Russo said. She couldn’t exactly how many Web pages were unavailable to Comcast users. The problems were “very isolated, very random,” she added.

“Google engineers helped troubleshoot the problem and provided diagnostic information to the ISP. We believe the issue has since been resolved by the ISP,” the Google spokesman wrote.

Postings in discussion groups and blogs seems to indicate the problem hit the northeastern part of the U.S. the hardest, specifically Boston.

This wasn’t the case out here in San Francisco, where I Googled all day long without problems.

Could you go a day without Google?

The outage included this blog, and it was strange in that it affected only sites that require cookies. So for example, I could search Google, but I couldn’t check Gmail; I could view my blog but not log in. How could a DNS server failure do that?

But Gmail hasn’t fixed a much more serious problem, in my opinion, one that I pointed out two months ago: your Gmail account appears in the “Sender” and “Return-Path” fields of your email header, even when sending as another account. The result defeats one purpose of using other addresses: keeping your Gmail account private while being able to conduct business with other accounts.

Gmail’s “Accounts” feature lets you send emails from different addresses. I’ve been using it to send emails from my work email address, and emails sent to my work address forward automatically to my Gmail account. That means I can organize, send, and receive all my emails from one central location, without giving away my private email address. Or so I thought.

I just discovered that even when you send email “from” another account, Gmail includes your Gmail account email as the “sender.” The screen-shot of a recent email’s header shows what I mean. Here I sent the email while logged in to my if.website#nosp@m#gmail#h.re#com Gmail account. I sent it as “webmaster#nosp@m#ilfilosofo#h.re#com”, but it says the sender is “if.website#nosp@m#gmail#h.re#com”.

I can’t think of any good reason to make that address public, and worse, nothing in the “Accounts” pages warns you that this will happen.