The two-columns elements are not expanding to fit the entire width if using Firefox or old IE (untested) and using a narrow window.
The following two selectors are being overriden
Code: [Select]
Making them !important fixes the problem.
The following two selectors are being overriden
// Two columns become one if viewed on a small screen.
@media all and (max-width: 800px)
.two-columns
width: 100%
margin: 0
Making them !important fixes the problem.