Do you copy the link straight from the URL bar when you are on the page that you want to share? This is the best way to make sure the link goes to the page you want it to.

Sometimes if copied from another site/page/forum a link will only partially be copied, so then it is broken when others click it.
It may work for you , because you may have the cookies to the correct page in your computer history from reading that page previously.

Tips-
http://www.computerhope.com/issues/ch000867.htm
http://www.wikihow.com/Copy-and-Paste-a-Link