Ok you stylesheet Gurus out there!

Can anyone help me to figure out why this page (http://www.mjmmagic.com/store/testim...timonials.html) looks fine, but when you click the button near the bottom to add a new testimonial, the layout is shrunk and looks like this:

https://www.mjmmagic.com/store/custo...nials_add.html

If you need me to post any files for examining, let me know. I suppose viewing the source code on the pages may help you, but I certainly couldn't make sense of it all.

Thanks!