[J2] Newbie: Error 404 with login portlet

[romain bisse]

Hi,
 
I've just installed Jetspeed2-M1 on Weblogic 8.1
Most of the modules work fine, however, I can't log in.
 
I obtain a 404 error when I clik on the login button.
There is no exception, neither in jetspeed nor in weblogic logs.
 
The URL in my browser at this moment is
"http://localhost:7001/security/login/proxy";
 
Did I forget something during the installation process?
 
Thanks in advance if you have any clue!