As someone who worked on an internal NHS website I can affirm this. Rather than use the same CSS and HTML for a form no matter which page it appeared on, the original coders had re-written it from scratch every single time, with slight differences (some intentional, some bugs) between them all.

Oh, and the entire site didn't work in IE6, it was developed / tested entirely targeting Firefox, despite the IE6 requirement being in the spec (and it ONLY needing to work with IE6).