I'm a web application developer, who runs a site http://myfav.es. We've been struggling with this issue for about a month now.
We use the HTML application cache spec - www.w3.org/TR/offline-webapps/ - with dynamically generated manifest files - myfav.es/personal.manifest - to speed page delivery. These dynamically generated manifest files use proper headers, and PHP to serve up custom manifests for users.
We also use gzip compression to serve the site from a linux/apache host.
For the life-cycle of our site, users report getting a err_failed similar to this screenshot in chrome. twitpic.com/272237.
This error is intermittent, occuring once every 200-300 visits, but will persists on every page refresh, including hard refreshes, which presumably means that an error using app cache is causing them to continuously load a failed version of the site. However, mysteriously JUST clearing cookies causes the error to fix itself.
I'm completely out of ideas on how to approach this error, and googling the error message appears to get a ton of confused users with voodoo-ish approaches to solving it. I've personally seen the error, along with a number of complaint from other users of chrome, so I'm fairly certain it cannot be caused by a particular user having abnormal settings or browser preferences.
Does anyone have any insight into the cause of this browser error and its origins? Whether its likely server-side or a byproduct of app design?