Problem with Password Field

I installed the plugin successfully. Highlighted the copy I'd like to protect, it added the tags correctly. When I view the page with the protection here is what happens:

In firefox: the field where you're supposed to enter the password isn't visible at all. There is nowhere to put the password.

In Chrome: the field is there, but when you click on it and hit the first letter of the PW, the field completely disappears.

Here is the page in question: http://cumberlandholdings.com/?page_id=339

Thanks in advance for any help. I'm a bit desperate here. And it's time-sensitive. Sigh, please help.