HTTP::respond and HTTP::version

I'm working with an LDAP authentication setup where we use

 

HTTP::respond 401 to prompt the browser/user for thier credentials. We have a problem with .net clients not responding to the 401 and we believe this is because the .net initial request is HTTP/1.1 but the HTTP::respond 401 is coming back HTTP/1.0 I've tried using the HTTP::version command in a HTTP_response it doesn;t seem to have any effect. Any help would be greatly appreciated.

 

Thanks,

 

Jason