Cannot log in on my dealer websites

[tater]

I have a new iphone 4s. I have several websites I go to and once I am at the home page, I need to click on dealer login and I get a response that, safari cannot find the server. I can get on my windows laptop and get right in. I have no problem logging in with my Samsung Galaxy tab. I had my friend with a iphone 4 try and he gets same message. Had another buddy with a droid phone try and he was able to get right in. What is going on? I tried to login with an Imac and had the same problem, but when I went through chrome on the Imac it logged in fine. Can someone tell me whats happening? I am tempted to go back to a droid.