Shibboleth Developers

I Posted this in Shib-Users 
[2009-10-16 11:46]:
> Something weird happened to me, certain users get slow connection when 
> trying > to access  shibboleth protected ressources.
> All of them are behind a NetAsk firewall.
> In my own opinion it could be some strange packets analysis made by the 
> client's firewall.
> What can I do to fix it.


Peter told me : 
>>Unless you can prove that mod_shib is the culprit (i.e. once you
>>un-protect a resource from Shib access is fast), you're asking this on
>>the wrong list.
>>-peter

That Why I post my question here again.
And yes I can prove it, the same ressource without shibboleth work very well.
I can not change the firewall.
Maybe not to put the SAML answer in the header ? could I ?
My config IDP and SP version : V 1.3 Apache 2 with tomcat modJK 

Best regards.
Hoping someone can help me.

David