Problem connecting with server when installing plugin

I am getting error messages when I try to install different plugins. I am going to the Plugin Browser/Installer link and then I select the file to be installed. However, after I enter all the information (hostname, user, password) I receive an error message that there is a problem connecting to the server. I have double checked all the ifnroamtion, including the hostname and I’m still getting the same error message.

Please tell me waht could be the problem.

Thank you,
Ana Popov
http://www.mangofusionjewelry.com/blog