had done the jailbreak on your iPhone?
if so, if you have the program Tiny Umbrella must go to advanced and uncheck the second square (one related to Cydia) .. then restart iTunes.
or open and edit the hosts file:
This quick tutorial explains the simple steps needed to edit the hosts file in Mac OS X.
Note: editing the hosts file can have very negative effects for web browsing if you are unsure of what you are doing. So, we take great care!
Further ado, here is the tutorial:
1. Open the terminal. To do this, open the ”Applications” folder, select the folder”Utilities”, then double click ”Terminal”;
2. At the terminal prompt, type the following line:
and press ”Enter” key on keyboard;
3.At this point, you are prompted to enter your password. Type it and press ”Enter” keyon keyboard;
4. The hosts file is now open in TextEdit. From here you can make the changes thatyou deem most suitable;
5. Once completed the changes, save the file;
That’s it - you’re done! You can now close the terminal. If we still need to re-edit the hosts file, just follow the instructions from the beginning.