Strange things with VirtualHost

Hi

I observe very strange things with Virtual Hosting :

I have defined a Virtual Host within two PassDirectory (HOST1,HOST2)

To consult documents and browse HTML files resources, I have no
problem... http://HOST1/SubDir1/SubDir1_1/File.html works perfectly.

But, when I intent to get an URL such as
http://HOST1/SubDir1/SubDir1_1/ to have the directory index I could
have two special results :
If I forget the last '/', I have the HTTP Error :
Resource unavaible :  
http://HOST1/HOST1/SubDir1/SubDir1_1 
And if I put the final '/' for the request , I have the Index, but all the
references are :
http://HOST1/HOST1/SubDir1/SubDir1_1/File1.html
http://HOST1/HOST1/SubDir1/SubDir1_1/File2.html
http://HOST1/HOST1/SubDir1/SubDir1_1/File3.html

So why does the server duplicate the HostName (PassDirectory name),
using a Virtual Host ?

A few hints to help :
I use a Jigsaw Alpha1.05 
I use a Netscape Gold 3.10

						RAF