UPDATE: Demo of problem here: http://jsfiddle.net/fdB5Q/embedded/result/
From about 767px to 998px, the form fields are wider than the containing well.
Smaller t
The input html tags and their corresponding .input-* styles only set the css width. This is by design.
.input-*
width
But adding a css max-width:100% will ensure that too large inputs are kept under control. e.g. add this to your Head:
max-width:100%