I am not a computer expert but I think you have the link pointing to a picture. The link ends in png and that usually idicates its a picture. In FF in the left menu that goes down the side there is a link that says Sharing. Put your mouse on that and another menu will pop up. The second option is Home page set up, Click there!
You should then see that it says: Your charting home page web address: (purple back groud)
Then under that in a box it should have an address.....
Something like:
http://www.fertilityfriend.com/home/#here (or name here for those that pay for the service can change it to something more personal rather than some random #. Dont actually click on that link because it will just take you to FF and it will say the home page you are trying to view is not available, or something like that.)
If you copy that address then your link should work. I hope that fixes the problem....