"HTTP request status Fails" error

Your Status report page located at admin/reports/status returns the following error

HTTP request status Fails
Your system or network configuration does not allow Drupal to access web pages, resulting in reduced functionality. This could be due to your webserver configuration or PHP settings, and should be resolved in order to download information about available updates, fetch aggregator feeds, sign in via OpenID, or use other network-dependent services.

The most likely cause of this error is

• A files format (character set) has been changed. For example when editing then saving your file your text editor changed the file format from UTF-8 Unicode to Latin1. Some text editor will change the file format without asking. Sometime inserting line brake or changing some characters.
• A file got corrupted during transfer. For example while uploading a file via FTP.

To fix this here are a few things you could try

• Deactivate all contributed modules. Test if error is still there. If error is no longer there isolate the error by reactivating only one contributed module at a time. Test each contributed module if error is still there. When error shows you will know which contributed module causes the error. Replace appropriate contributed module file(s) with fresh file(s).
• Install the module 'http_request_fail_reset' http://drupal.org/project/http_request_fail_reset
• Add a line of code at the bottom of your settings.php file http://drupal.org/node/245990#comment-1312270
• Read more about the error source. For developers. http://drupal.org/node/245990