This might seem like a stuipd question but I need you to look at the address bar on your browser when this is going on. what is the address for the site listed as?
The message you list is a message that is displayed if someone links to an image off this site and posts it on another site. if the site address is not aquariumadvice.com in your URL then you will get this error. Now I know you think im on crack or something because how else can you be on this site and have the domain in your address bar say something else. Well it could be your somehow using an old favorte where your using the wrong domain name.
for example when we moved this site to its new host for a day the address was http://demo.sausagehosting.com/~aquacon/
well that address will still work if you use it but non of the images will show up because that domain is not authroized to link to our images.