Hi Isaias, thanks for your help.
It sounds weird the SAPWEBDISPATCHER and the Enterprise Portal (our website) should be in the same server.
We expect and know that our end users mustn't access the default URL and only the website that we are configuring.
I am going to configure a SAPWEBDISPATCHER in the same server of our Enterprise Portal and will tell you the result.
Thanks Isaias for helping us with this configuration.
Marcos.