If you have Norton Antivirus, there are some files that interfere with Zone Alarm unless specifically granted access to the internet by Zone Alarm. Look on Symantic Support and find "Document ID:2003082012355706 Last Modified:05/19/2004". I followed the instructions to permit Zone Alarm to allow access by all the Antivirus progrm files and it seemed to workfor my Outlook Express problems, it may work for IE6 problems.
I have recently updated ZoneAlarm and now can't connect to the internet. I have tweaked the settings and tried uninstalling and reinstalling the application, which worked on a previous occasion, but no luck. I can ping IP addresses but can't connect via IE6 and suspect there are rogue settings somewhere in the registry that is causing the problem.
Any suggestions appreciated.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic