Shoutbox

I can login to a certain website using this laptop but if i try and use my friends laptop it just ignores the fact ive logged in and asks me again and again

ive check the cookie settings
tried it with the av disabled
tried it with the fw disabled
tried it in firefox after installing it and it does the same thing

its looking like a cookie issue (im not having trouble with password etc, i can login fine on this machine) but i dont knwo why the cookie is being a twat or why the websites being a twat

please help!

thanks