Unfortunately we do not have the resources to investigate large bug
reports; please try to construct a minimal example of this problem.
There are some hints here:
http://lilypond.org/web/devel/participating/bugs
This particular case looks like a rhythmic problem, so I'd normally
suggest that
First of all, I don't think it's a bug. It's rather an example of an ill
chosen
line break (or rather an unfortunate choice of LilyPond not to include a
line break). It seems that the line breaking mechanism in LilyPond
thinks that
the full piece is short enough that everything can fit on a sing