All the networking error pages have a "Try Again" button, but for some errors, trying again will always result in the same error message (illegal hostname, blocked port, etc). The "Try Again" button should be hidden for these messages. (Discovered by OnoSendai[wrk] in #firefox.)

Could throw something like this into netError.xhtml's initPage(): switch (err) { case "malformedURI": case "protocolNotFound": case "unknownSocketType": case "deniedPortAccess": case "proxyResolveFailure": document.getElementById("errorTryAgain").style.display = 'none'; break; default: break; } Not real sure about the list. It's possible for someone to change a setting in about:config or the prefs dialog that would make Try Again useful...

Not sure that I'd hide Try Again for DNS errors. It wouldn't be that uncommon to have someone managing a nameserver (web control panel or other) retrying the op after making changes to a zone. The nameserver could be screwed up, in the middle of a restart, or on a short delay before it receives the updates and reloads, etc...

The "Try Again" button is completely useless on Firefox's "This address is restricted" page. The error message for that page is "This address uses a network port which is normally used for purposes other than Web browsing. Firefox has canceled the request for your protection." The port will still be blocked no matter how many times a persistent user clicks "Try Again".

at least in windows, the "try again" would only be usefull in dns errors, if firefox flush the dns cache first, if not, it will always give the same result (unless ones wait for the dns retry time) if FF runs a "ipconfig /flushdns" in each "try again" press it would be useful, if not, there is no difference in a user press reload for linux, usually there isnt any dns cache in the client side, but sometimes if can exists, so instead of hardcoding the "ipconfig /flushdns", a about:config option that allowed one to finetune the correct command to flush the cache i have no idea on mac :)

If this is a meta bug, bug 553180 is worth remembering. And please note that "malformedURI" and "protocolNotFound" came back to the error page (bug 312680 and bug 382702), UI reviewers.