two Marvin applets on one page now forbidden?

On this page, two Marvin 4.1 applets appear side by side, no problem.

On this page, otherwise identical, only one of the Marvin 5.2.3.1 applets appears; the other does not.  ???

Also, my Safari error console tells me when I load Marvin 5.2.3.1:

ReferenceError: Can't find variable isLeopardSafari	:9183/nosession/marvin/marvin.js:295

-- Bob

ReferenceError: Can't find variable isLeopardSafari	:9183/nosession/marvin/marvin.js:295

In earlier version of marvin.js, the isLeopardSafari method was missed. We have fixed this bug in Marvin 5.2.4.

I suggest upgrading Marvin Applets to a newer version.