Automatic breaks not working?

[asentman]

I have a couple of files where Lilypond fails to wrap the score across
multiple lines, and instead cuts it off at the edge of the page. Most of
these are fairly large files, and it seems to happen consistently if there
are more staves than can fit vertically on the page.

What I did: I used lilypond to render the example at the bottom of this post.

What I expected: The score wraps to the next line after the sixth measure.

What happened: The score does not wrap, instead running off of the edge of
the page.

Sorry for the long example. Removing any more makes the issue less clear in
the output.

Example:

\version "2.16.2"
\language "english"
\score {
        \new Score <<
                \new Staff {
                        r4
                        r16
                        c'16
                        r4..
                        c'16
                        r4..
                        c'16
                        r4..
                        c'16
                        r4..
                        c'16
                        r4..
                        c'16
                        r4..
                        c'16
                        r4..
                        c'16
                        r4..
                        c'16
                        r4..
                        c'16
                        r4..
                        c'16
                        r4..
                        c'16
                        r4..
                        c'16
                        r4..
                        c'16
                        r4..
                        c'16
                        r4..
                        c'16
                        r4..
                        c'16
                        r4..
                        c'16
                        r4..
                        c'16
                        r4..
                        c'16
                        r4..
                        c'16
                        r4..
                        c'16
                        r4..
                        c'16
                        r4..
                        c'16
                        r4..
                        c'16
                }
                \new Staff {
                        r1
                        r1
                        r1
                        r1
                        r16
                        a'8.
                        a'8.
                        a'8.
                        a'8.
                        a'8
                        d'16
                        d'16
                        d'8.
                        d'8.
                        f'8.
                        f'8.
                        f'8.
                        f'16
                        a'8.
                        a'8.
                        a'8.
                        a'8.
                        a'8.
                }
                \new Staff {
                        r1
                        r1
                        r1
                        r1
                        r1
                        r1
                        r1
                        r1
                        r1
                        r1
                        r1
                        r1
                        r16
                        d8
                        e8
                        a8
                        a,4.
                        d4.
                        c4.
                        f2
                }
        >>
}