\startxtable[spaceinbetween=0cm]

  \startxrow

    \startxcell one \stopxcell

    \startxcell two \stopxcell

  \stopxrow

  \startxrow

    \startxcell alpha \stopxcell

    \startxcell beta  \stopxcell

  \stopxrow

\stopxtable

I cannot follow the behaviour of spaceinbetween.

When absent the rows are put neatly against each other.

But with spaceinbetween=0cm there is a gap, that does not seem to change with either changing the dimension or replacing it by small, medium, big, or even none. 

Could there be an error in the code for xtables?

Hans van der Meer