Topic: Simple Viewer

I started to use the Simple Viewer few days ago.

I have one problem.
I added it to 'iframe' but Mozilla Firefox can't open it. I can see only 'X'-es in the box. If I right click the 'X' and open in new window, can see the photos.
MSN Internet Explorer can open it and don't have any problem with it.

Is someone has/had the same problem?

Thanks in advance for your help.