The status code returned from Server was: 12031

Recently the website which was working fine started throwing this error on one of the user's machine when the user clicks the button on a page . All the controls in this page are wrapped inside an update panel and at the top level ToolScriptManager is present

Sys.WebForms.PageRequestManagerServerErrorException: An Unknown error occured while processing your request on the server. The status code returned from Server was: 12031

The web page is not having much data and i am not storing any data in view state(as this was the cause mentioned in earlier threads).I cross checked the httpRuntime tag in web.config and it as below.

<httpRuntime executionTimeout="210" maxRequestLength="102400" requestLengthDiskThreshold="80" useFullyQualifiedRedirectUrl="false" minFreeThreads="8" minLocalRequestFreeThreads="4" appRequestQueueLimit="5000" enableKernelOutputCache="true" enableVersionHeader="true" requireRootedSaveAsPath="true" enable="true" shutdownTimeout="90" delayNotificationTimeout="5" waitChangeNotification="0" maxWaitChangeNotification="0" enableHeaderChecking="true" sendCacheControlHeader="true" apartmentThreading="false"/>

Can some body help with this issue or give some clue what might be appropriate place to look for to fix this issue. I googled and few threads mentioned that it is WinInet API Error with the status code mentioned as

   12031       ERROR_INTERNET_CONNECTION_RESET
               The connection with the server has been reset.


Has it got something to do with the network connection on which the user machine was , or is it related to the page that thrown this error..?