I'm in the same situation, and I hope this never gets a fix from Google, as like you I like being able to tell the difference when the tabs are too small to show the email address.
That is the favicon for the Google Apps Admin Console - https://admin.google.com/ . I suspect the bug only happens for Google Apps accounts (it happens on my Google Apps, not on my personal Gmail).
I thought I read that it shows up for a google app account that is also the domain administrator. But I'm not sure if this is true or not. I wouldn't say this is a "fix" as much as it's a work around for showing that other favicon.
There's also a Gmail Labs feature to display unread message count in the favicon ("Unread message icon by Manu C"). That is both super-useful and fixes the favicon issue.
Dammit, I completely read the article wrong. Labs wasn't capitalized, so I didn't grok it correctly. Well, it saves you clicking on the article if you just came straight to the comments...
I noticed this about a week back in our business account. If you view the page source, the favicon actually points to a favicon in a your company's folder (for Google Apps). I have a feeling they will allow us to customize the icon shortly from their admin panel.
That's clearly true. But if you are like me and tend to have dozens of tabs open, the favicon change makes scanning for Gmail a lot harder which is annoying. That it is also ugly is adding insult to injury.
Oh the ugly spanner icon turned up on my works gmail a week or two back and its been bugging me to bits!
Why was it showing a spanner? It made no sense to me. A bug in gmail perhaps? But if it affects so many people, why haven't google noticed it before then?
I stopped using the "Unread Message Icon" a while back because it would often get "stuck". How does a screw-up like this go unfixed for so long anyway? It's been at least a week. It's only a favicon!
