My technical support people just installed IE 6.0 on my system and it's returning the same bad results as Flareup. (Actually, in my case it just goes to "Thanks for logging in!
Sit tight... We are taking you back to: [url=http://..."]http://..."]http://..."[/url][/url] and then never does anything else.)
I can still login to my UBB Control Panel.
I'm on Win2k and UBB 6.1.0.3.