In Internet Explorer, if you cannot un-check the "Check for server certificate revocation" check box on the advanced tab of the Internet Options dialog, and you have a Norton 2008 product, then the fix is as follows:
1. Uninstall the Norton Product. 2. Run the Norton Removal Tool. You can find a link to it in this post.
When you've done that, your Un-Check will be kept after you click OK.