[NTG-context] suppressing page number on an empty page

Dear list members, I want to suppress page numbers on empty left pages before a new chapter. I tried: \setuphead[chapter][page=yes,before={\ifodd\realpageno\else\page[empty]\fi}] This works, but messes up the layout. I then tried to do it manually: \page[empty] or \page\noheaderandfooterlines at the appropriate places, but this also completely changes page breaking in the following chapters (e.g. text running down over and beyond the pagenumber at the bottom with \page[empty], or just breaking a page at a different position, which would force me to reposition all the margin figures etc.. Is there a trick to avoid this behaviour? Thanks for your help, Jörg