Hi Whits,
Microsoft has a toubleshooting guide at its
knowledgebase
http://support.microsoft.com/default.aspx?scid=kb;en-us;813444]IE6.0 troubleshooting guide[/url]
This applies if you are unable to browse through HTTPS sites in Windows XP...........
SUMMARY
Delete Temporary Internet Files
Configure Security, Content, and Advanced Settings in Internet Explorer
Verify That the Date and Time Settings on Your Computer Are Correct
Verify That Your Computer Is Using 128-Bit Encryption
Use System Restore to Return Your Computer to a Previous State
Check Third-Party Firewall or Antivirus Programs
Use the System File Checker (Sfc.exe) Tool to Verify Protected System Files
Verify That the Microsoft Cryptographic Services Service Is Started
Register .Dll Files
Create a New User Profile
NOTE: Create a New User Profile has
resolved the issue in many occassions.
Good luck and happy computing
Steve