[NTG-context] 90° rotation + landscape

Hello list, I want to setup an evelope and the whole output should be rotated by 90° (this is the way my printer gets them). ___ | || ________ | | | -- | | | |_____--_| ||__| normal layout 90° rotated output (paper and content) The resulting pdf looks like this (square paper format): ______ | | | | | | | ||_____| Here is a minimal example: % interface=en output=pdftex \definepapersize[C65] % standard C65 evelope [width=229mm, height=114mm, ] \setuppapersize[C65][C65, landscape, 90] \starttext \tfc 90° rotation for printer. \stoptext Have I missed something or is this a bug in \dodosetuppapersize? Any help welcome, Peter