Rich Text Area in Firefox 32 (Ubuntu) - shortcut keys not working

I’ve just been playing around with the rich text area in the demo (
http://demo.vaadin.com/sampler/#ui/data-input/text-input/rich-text-area
) and shortcut keys aren’t captured.

For example, Ctrl+B opens the bookmarks menu rather than toggling bold.

Wondering if this is a known problem and if there’s a workaround?