Strange Installation Issue

[nikitas]

Hi . . . congrats for the excellent work!!!
So this is my story :-)
I recently installed prestashop . . . at a windows xp ( sp3 ) pc with wamp server v2 on it.
After the installation i (and douzens more) could not login !
Here are my steps ->
I have changed the vhosts file of Apache with this
NameVirtualHost 127.0.0.1

ServerName w w w .p r e s t a s h o p . g t
DocumentRoot "C:/wamp/www/prestashop"

and added at c:\windows\system32\drivers\etc\hosts
the site name -> www.prestashop.gt
in order to have access via www.prestashop.gt
at my browser (firefox as default) as i usually do in order to test (local) any site.
So when i try to login with firefox nothing happens i get the same error !!! (see atchmnt image 2)
Now when i try to login via ie6 i dont have any prob there !!!
i can login with the www.prestashop.gt address to !!!!
So this is pretty strange !
Why firefox doesnt accept via www.prestashop.gt and does nt have a problem via http://localhost/prestashop/admin752

Can u please tell where is the prob?
I enen installed cookie cleaner or something like that as an addon from firefox->extras->addons but nothing!
Does it have to do with firefox only or with other browsers to?
if i run as standalone php script via the include command with something like session_destroy will it work?
And where do i have to place it in order to work?
I have manually inserted to firefox at the cookies tab from tools->options etc to trust cookies from this site so where am i wrong?
P.S Thanx in advance!
P.S 2 excuse my poor english