If you are writing a Facebook application, you need to make sure that your proxied pages (the pages that Facebook gets from your site when someone requests a Facebook page that corresponds to your application) return in a timely fashion. If they take too long to return, users get the following error on Facebook:

There are still a few kinks Facebook and the makers of [[your application name gets shown here]] are trying to iron out. We appreciate your patience as we try to fix these issues. Your problem has been logged - if it persists, please come back in a few days. Thanks!

To avoid getting this error, make sure that your pages that are proxied by Facebook get returned in 12 seconds. If the response takes any longer, users will get the error message shown above. Yeah, no web page should ever take that long to return. But if you are getting anywhere near this limit, network latency could add enough delay to push you over the top.