Hairpins not lining up

[Nick Payne]

\relative c' {
        \stemDown
        \time 3/4
        e'8\< d c\! d\> e c\!
}

I have the notes and dynamic marks shown above in one bar of my score. For
some reason, in the complete score the crescendo and decrescendo marks are
not aligned horizontally (see png), whereas when I excerpt the phrase to a
small example as above, they do line up.

There are quite a number of places where this same misalignment occurs. I
realize I can explicitly set the staff-padding value for the marks to get
them to align, but this is a fair bit of stuffing around. Has anyone any
suggestion why this misalignment happens?

Nick

hairpins.png
Description: PNG image