fatal error: memory exhausted

Try increasing the memory available to PHP.

It can also be a problem with your hoster. I had the same problem with an old 1&1-hosting-package with only 32MB Memory. With many plugins some day there was the same problem.

By the way: your website ist with 773kB a little heavy and slow.

Do you have still the mistake, when you deactivate “fancy-box”?

Oh YAY!!!
That fixed it!

How do I add memory?

See the link I posted above.

With a modern hosting package with e.g. 128 MB Memory Usage. Please ask your hoster.

@esemi: That does not help in every case, it depends on the hosing agency

Which is why Step 4 is “Talk to your host.” ??