If I try the following in ConTeXt:
\starttext
text text\inmargin{this is a note.} text text\inmargin{Another note.}
\input knuth
text text\inmargin[stack=yes]{this is a note.} text text\inmargin[stack=yes]{Another note.}
\input knuth
text text\inmargin[stack=yes]{this is a note. Now longer.} text text\inmargin[stack=yes]{Another note.}
\input knuth
\stoptext
then it only works for short notes. For longer notes I found the suggestion to use stack=continue, but I could not make that work either.

So my question is: How to make it work with floating (not overlapping) text [edit: in MKIV]?
EDIT1: It only does not work in MKIV , MKII is fine
(ConTeXt ver: 2011.05.18 18:04 MKIV fmt: 2012.5.8 int: english/english)
(ConTeXt ver: 2011.05.18 18:04 MKII fmt: 2012.5.11 int: english/english)