Occasionally I would get the above error when posting a new thread or replying to an exiting one. It's an annoying problem because the text I typed would be lost.

Today I fixed the problem and thought I'd share the solution because I'm sure others will benefit from what I found.

The Symptoms:
This only happens using Internet Explorer. Firefox and Google Chrome work fine. The problem only happens when the site is slow. Clicking the "diagnose network problems" button returns no problems. Reattempting the same action that caused the above error usually will work the second time. Or by simply continuously clicking the submit button over and over will eventually submit the post, sometimes a duplicate. Also receive the error when searching and using the "my recent topics" options.

The Problem:
There is a time out issue with the IE browser. In my case if the web site had not responded to an action in 10 seconds the above web page would pop up. The error is not descriptive, it should say "timeout".

The Solution:
Run "regedit.exe"
In the left panel follow the path to HKEY_CURRENT_USER\Software\Microsoft\Windows\Curre ntVersion\Internet Settings
Once you have found the above path, right click on RecieveTimeout in the right panel.
From the popup menu select modify. The setting on my computer was 10000 milliseconds, or 10 seconds. Note that you should click "decimal" to get a human readable number.
Add a zero to the end of the number making it 100000 or 100 seconds. That should be plenty.
Exit out of regedit.exe
restart your browser.
Problem will be solved.