I can't get grip on spacing

Can anybody explain me what is happening with the spacing?
My trumpet part is 3 pages long (A4 landscape), with a lot of white spacing between the staves. I’ve change the vertical spacing in layout options. The first page looks good now, the second page has different spacings.

What is the correct way to do this? I’m writing for marching band and have to put music on A4 pages landscape. Finally the music where printed on A5.
Schermafbeelding 2017-01-04 om 10.47.53.png

Almost all the spacing looks right to me. The first page’s spacing between systems might be slightly more compressed due to the header text. The only thing that is close to being obvious is the second “f” in measure 58 might be causing the spacing to inflate there. That’s all I can see. A little extra vertical space is given between systems that have rehearsal marks (versus those that don’t), but nothing out of the ordinary, IMO.

I agree with tisimst. But another oddity to my eyes is the collision between rest and beam on the first page, where there are off beat quaver E-flats (later Es). I dont know what the rules are for this, but to my mind, either the beam needs to be lower, or the quaver rest higher.

David