[NTG-context] remove extra vertical offset in tabulate

Dear list, I have the following sample provided by Hans (and tweaked by myself): \setuptabulate[offset=overlay] \definelayer[MyLayer][state=start] \setlayerframed[MyLayer][align=normal,offset=overlay] {\setuptabulate[before=,after=] \starttabulate[|l|l|] \NC one \NC tab \NC \NR \NC one \NC tab \NC \NR \stoptabulate} \definelayer[OtherLayer][x=20mm,state=start] \setlayerframed[OtherLayer][align=normal,offset=overlay]{one tab\par one tab} \setupbackgrounds[page][background={MyLayer,OtherLayer}] \starttext \input knuth \stoptext How can I suppress the extra vertical offset added by tabulate? Many thanks for your help, Pablo -- http://www.ousia.tk