It might not be the/a problem but I can see it dropping the other headers while doing a redispatch depending on the engine. This issue caused an extremely bizarre and maddeningly difficult bug in some modperl I worked on once (it would execute an entirely unrelated handler on some relative redirects). The point here being, it's wrong as is and when you break standards you get unspecified behavior whether or not it's causing the bug your users are reporting. Try patching it. Verify it's reasonable in your own environment (I didn't test it though I've done a lot of this stuff) then push it out to a user who is seeing the bug and get some feedback.

I know exactly what you mean about the standards thing, especially in IE. I've got the code updated using the proper URI. I'll report back in the am when I've heard back from the users.

Nope, didn't help :\ One of the users who couldn't initially save cookies and login can access it from a different computer in the home successfully. Now I've got 2 more people having the same issue though. I'm stumped.