Dave Cheney Wrote:
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> So, to confirm, there is no record of the request
> at all in your
> access log?

Nothing. I set the log level on the error log to debug also to see if that would force something into the error logs, but nothing.

But facebook is telling you that it
> could not contact your
> servers (sorry, I have no experience with writing
> facebook apps) ?
>
I'll try to explain as best I can. The request that generates the errors is not going through facebook, that's how we know it's nginx because the page displays the raw nginx error page with the nginx version number and all. That page is inside an iframe on a facebook canvas page. The iframe loads pages directly from our server. Inside the iframe is also some fb javascript code that loads a proxy file from our server directly to handle cross domain iframe communications, and at the same time sets cookies on our domain. We think it's the facebook javascript code we are running in our iframe that is setting the cookies that nginx doesn't like. We are pretty sure about this because some of the banner ads we run on other pages of our site are also facebook connect iframes, and they also have the same effect. Once they set a bad cookie, all the images on the facebook canvas which reference our servers start to break due to 400 responses.

Chris