[NTG-context] \startframed spurious whitespace

There appears to be a bug with \startframed. In the following example, the instance with no optional argument sets correctly, while with the use of an optional argument (even empty []) a whitespace is introduced before the text. \starttext \startframed[] Why a space? \stopframed \startframed This is ok. \stopframed \stoptext -- Rik