[NTG-context] page break before box

Sometimes I get page breaks before a box as follows (didn't manage to write a minimal example): Some text on the page (even one line only) A small box (much smaller than the empty space on the preceding page) \page[no] and \dontleavehmode don't do anything. Example for a box: \definestartstop[Point][before={\setupbackground[background=color,backgroundcolor=lightgray, frame=on,framecolor=red,topoffset=0.25cm,bottomoffset=0.25cm,leftoffset=0.5cm,rightoffset=0.5cm, before={\blank[big]}]\startbackground},after=\stopbackground] Something simple, surely? Jörg