If you do not own or rent your own dedicated server then you may come across an issue when you try to include a url. The issue comes when your hosting company has it disbaled in the php.ini file.

There are alot of hosting companies that have the global setting disabled but allow you to have a local php.ini file. If this is the case then you can change the setting by adding a php.ini to your main directory such as public_html. In this case you would add the allow_url_fopen = 1 to the php.ini file.

You can also setup your SAFE_MODE options this way. Sometimes hosting companies limit the local changes you can make so some of the options may not work with a local php.ini.