Right fieldset border in DA created forms missing

This is because you have an
#outerWrapper class defined with width: 800px (screen.css line 94),
and your contentWrapper has a right margin of 180px (screen.css line 124)

That means you only have 620px left over for the form, and your form is set to 760px (/webassist/forms/fd_basic_default.css line 22)

You also have a class fullColumnGroup used inside the form that won't fit (fd_basic_default.css line 22)

Try updating the form to 610px and set the fullColumnGroup width to 580px

It looks like you have been playing around trying to fix this and added code to screen.css line 143 trying to set the right border of the fieldset... remove that.

That should get your page displaying the way you need it to.