Question about uuid_generate_v3

Hi,

First of all, I am new to this list and I'm not sure if it is the
correct one to post technical questions. If it is not please tell me
which one I should use.

Recently I installed postgresql 9.1beta3 on a Windows 7 machine to start
testing uuid generation. I correctly installed the functions in my
public schema, however when I run the following sql sentence SELECT
uuid_generate_v3(uuid_ns_url(), 'http://www.cit.com') I always get the
same result "b2c61380-d1b2-3ca8-a63b-c45d4e0da06a".

Not sure if this is a bug or if I am doing something wrong or if I
missunderstood that uuid_generate_v3 should be generating differente
uuids in every different call to the function.

Has someone faced the same problem? in case of yes could you please
share your solution with me?

Thank you
Godofredo Contreras