i have found out that the problem isnt related to my Mac it is related to my IP address, i got in contact with my internet provider and they did a whole lot of tests and it was found that this website is filtering my ip, so i can access the site using a proxy.
i tried sending you a private message with my ip address but i cannot send one to you. could you please contact me privately so i can send you my ip so you can find out why the website is filtering my ip address?
Thanks