sfmhui said

The problem started to happen after we installed a sonic wall. Not sure if that has anything to do with it.

Disable this, then try again. If there is still a problem;

Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac Options) key, and then starting Firefox. Is the problem still there?

In what state is Firefox when this happens?

In connecting state Windows will terminate the connection quite quickly after about 20 seconds if that hasn't changed. Other browser might possibly retry automatically in this case, but in Firefox you need to retry manually. I'm on Linux and that OS behaves differently and it takes several minutes before Firefox gives up and shows the page that the connection has failed.

When a connection has been established and Firefox is in waiting state then Firefox on Windows should wait a lot longer for requested content before giving up.

See this old blog post about modifying a registry key:

• http://drewthaler.blogspot.com/2005/09/changing-dns-query-timeout-in-windows.html

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\DNSQueryTimeouts Multi String: "1 2 2 4 8 0" -> "4 8 8 16 32 0"

Here are a couple test pages that respond slowly. What do you get with these?

• http://jeffersonscher.com/res/sleep120.php -- takes 2 minutes to complete on the server and should return "Slept 120 seconds before generating HTML." (Firefox aborts its http request silently within 60 seconds)

• http://jeffersonscher.com/res/ajax100.html -- has a button to generate an AJAX request that takes 100 seconds to complete on the server and should return ok if the response was received, or ko if it wasn't (mozillaZine - error on long lasting ajax calls)

Thanks all for the responses but no luck. Here are the test results:

1. We tried to start with safe mode. Firefox is running on Windows 7 and we use "Help -> Restart with Add-on Disabled". No change. Also, the sonicwall I mentioned actually is a router (piece of hardware) from Dell. It's not an Add-on to Firefox in case there are any confusions.

2. The best to my knowledge, I think this is what happened:

   a) Firefox sent a request to the server
   b) server received the request and tries to process
   c) We can see Firefox spinning from the browser tab
   d) after a short period ( a few seconds to 30 seconds), Firefox stopped "spinning" but no update to the browser screen
   e) The server continued processing the request but couldn't return the result since Firefox already stopped.

3) The server was developed using ruby on rails, I created a page that sleeps for 90 sec and tried. Firefox does the same thing (sending request, spinning and stop). It is interesting that for a pure sleep, Firefox stopped much faster, maybe 5 seconds.

There is this prefs that deals with a connection timeout, but it defaults to 300 (5 minutes) and thus shouldn't have the effect you get.

• network.http.response.timeout

You haven't confirmed if Firefox is in connection state or waiting state.

Do you see ant status messages at the bottom of the Firefox window?

You can open the Web Console (Firefox/Tools > Web Developer). Check on the Network tab how fast content arrives (if any).

• https://developer.mozilla.org/Tools/Web_Console

Does this happen for the whole site, or just one page?

Can you post a public link for us to check?

Same problem on my test pages? https://support.mozilla.org/questions/1059958#answer-723703

If so, we could rule out an issue on your web server and focus in on your system or your network.