Can't move session data rightly

Hello, I posted at first time. so I think thet anyone help me .

I’m using the CGI/Session and XMLHttpRequest.

When client blowzer is FireFox, session data could exchange from server
and client rightly. But Internet Explorer6.0 can’t it.

The http header was right both of IE and FireFox.
Server is apache 2.0.59 + fast_cgi + mod_ruby.

Is this Bug of IE???

Nothing is information in the ruby.orgs webpage , ML, etc…

Are there available information?

thank you.