Prepare!

• Using IE7?
  
• Behind a proxy?
  
• Ever seen this error?
  

Then most likely, you (or IE7's anti-phishing feature, or an RSS feed, etc.) have tried to load some content from a server registered in DNS, but has not returned a result within 30 seconds. Afterwhich, all IE7 tabs with Internet-content become unresponsive, and IE7 continually reports the error listed in the subject of this post.

So, what's the answer? Simple: Inform IE7 never to mark your proxy as 'bad', using the BadProxyExpiresTime registry hack. Here's how:
http://support.microsoft.com/kb/320507

If this registry hack scares you, then here's a work-around: Toggle IE's "Work Offline" feature. To do so, pull-down IE's File menu, and select "Work Offline" -- then repeat, to enable online mode. This little trick should reset the internals of wininet.dll to allow browsing once again.