\setupoutput[pdf]

\starttext

Table with bad height of [upper third] cell:

\bTABLE[height=2cm]
  \bTR
    \bTD[nr=2] first\eTD
    \bTD[nr=2] second\eTD
    \bTD[height=1cm] upper third\eTD
  \eTR
  \bTR
    \bTD[height=1cm] lower third\eTD
  \eTR
  \bTR
    \bTD[nc=3] long last row\eTD
  \eTR
\eTABLE

\godown[2cm]

The desired look, but achieved by different settings:

\bTABLE[height=1cm]
  \bTR
    \bTD[nr=2] first\eTD
    \bTD[nr=2] second\eTD
    \bTD upper third\eTD
  \eTR
  \bTR
    \bTD lower third\eTD
  \eTR
  \bTR[height=2cm]
    \bTD[nc=3] long last row\eTD
  \eTR
\eTABLE

\stoptext