> I would grab a copy of Ethereal (or similar), and put a trace > on HTTP traffic. > > It appears that you are using a custom-built authentication > system rather than a HTTP-based authentication system (like > Basic Auth), so for this to work, the browser and server need > to properly maintain session state. It seems that this may be > getting "lost" somewhere along the line. > > Also, check your webserver logs to see what the server thinks > is coming from the browser. Hi Ken, Yes, Ethereal was installed on a couple client systems, and helped gather data, however, this particular one is off-site, and we won't be able to capture packets, unfortunately. Thanks for the tip re: session state. This is what it looks like to us as well. It's an odd one that only happens in IE 5.5 too. Webserver logs are next on my list. Thanks for the help! Chris.