Problems previewing scores longer than one page

[gethinwebster]

When a score becomes longer than one page the preview output seems to become corrupted. PDF download is fine, but the right-pane preview isn't.

I can potentially try to dig in and debug/fix this, but if anyone has any initial context/pointers (or if e.g. this is a known limitation that would require significant refactoring to fix) that would be useful.

Can be recreated with this score:

\header {
  title = "Untitled"
  composer = "Composer"
}

\score {
  \relative c' {
    \repeat unfold 1000 { c4 }
  }

  \layout {}
  \midi {}
}