This week I have a mystery that has been resolved but not explained. When the problem started I polled many very clever people but no one could give me an answer.

The mystery is this: I run Firefox 3.07 on OS X 10.4.11 to access Gmail. A few days ago, out of the blue, I found I couldn't log in. I entered my user name and password and Gmail returned to the login screen without an error message or anything apparently amiss other than I was back where I started.

Oddly enough, I could log in from the same Mac using Safari 3.2.1, as I could using Firefox 3.0.7 on Windows XP SP2.

A friend suggested that the Firebug plugin could be the culprit as it sometimes causes problems, but although I had been using it I had disabled it for exactly that reason a few weeks before.

In fact, in trying to figure out what was wrong I had disabled all of the Firefox add-ons on my Mac but nothing changed — I still couldn't log in. Even reinstalling Firefox didn't help.

Out of curiosity I thought I'd try to seek an answer using a new "social search" service (a search service combined with social networking) called Aardvark.

The idea behind Aardvark is interesting. It makes finding answers a social crowdsourcing exercise by asking users who claim domain expertise to deliver the goods. You, in turn, answer questions the service routes to you.

When you join Aardvark you create a profile and select topics you would be willing to address. To ask a question you instant message Aardvark (AIM, Google Talk and Microsoft Windows Messenger are supported) and the service routes your query to a random user who claims expertise in the topic area.

The routing is determined by the service "intelligently" inferring context from your question. Aardvark IMs you when it dispatches your question and tells you what topic it thinks applies to your question. If you disagree you can respond with a follow-up IM containing "tag:" followed by the topic you believe your question is about.

So I tried asking Aardvark about my Gmail problem and within 10 minutes had an answer that solved my problem! The solution didn't explain what caused the problem other than identifying it as a configuration issue, but at least I can now log in to Gmail.

In case you're wondering, the advice was to exit Firefox, navigate to my user folder, then go to Library\Application\Support\Firefox. I then moved the Profiles folder and the file profiles.ini to my desktop, which removed all of my cookies and other configuration settings. When I relaunched Firefox I could log in to Gmail once again. Of course all of my other settings are history but even so, the solution was fairly painless.