The innocuous hr tag renders quite differently across IE, Chrome and Firefox. In particular, on the last two mentioned browsers the hr was rendering with an indented border, which it didn’t in IE.
Searching for a cross-browser way to style hr I ended up at this very helpful forum post from HTML Help Central, entitled ‘Google Chrome With hr, but then had to tweak it a bit so that it worked across my browser family.
Here’s the final result for which I was awarded the VC, DSM, OBE and P-K4:
border-top:1px #dbdee4 solid;