Disclaimer: Check the date! This post was written way back in . Links could be dead or irrelevant. If there are technical things in here, they may be outdated, or there may be better ways to do them by now. You've been warned.
A bit of debugging and I found that the culprit was
table-layout: fixed, which was included by Bitters. A quick patch in my
main.scss file and we were all fixed: (As you can see by this working gist!)