In print.css, set overflow: visible instead of overflow: auto on div#content. That fixed it for me in Firefox at least. The definition of overflow auto is: “If overflow is clipped, a scroll-bar should be added to see the rest of the content” — but scroll bars don’t exist on printed pages.
I’m guessing that since the content div should span across multiple pages, the browser thinks “you’re flowing outside your container and must be clipped with a scroll bar”. The container in that case is the first page the content div appears on.