cant access one webpage

I need to know if my p.c has been set to block the my-space websight. this is a shared p.c and other users claim noone blocked the sight. i have deleted cookies,history,etc. Security tab shows no blocked sights yet i cannot access the sight w/out using a proxy. problem is i have to respond to a link that is sent to my e-mail to become a member. when i click the link i am unable to access the sight. a very frustrating situation, need some help people. thanks for any suggestions