🚀 go-pugleaf

I've got a problem with the information in the head of a page.
for a reason that i don't know, at the top of some pages appears the
wrong title of the current chapter. 

As described at page 83 of the LaTeX user's guide, I start my document
with

    \pagenumbering{roman}

and at the chapter where I want the arabic pagenumbering to be started
with the command

    \pagenumbering{arabic}

right after the \chapter command.

Only, at some chapters before the \pagenumbering{arabic} command
appears the wrong title at the head: a title of a previous chapter.

Has anyone an explanation for this behaviour.  I asume I did something wrong,
but i can't figure out what it is

R.Savenije