Hi,

The following example results in the error “You can't assign a
glue_spec node to a prev field”

\starttext
  \startcombination [2*1]
    {\starttable [|c|]
     \NC \math{1} \VL\NR\HL
     \stoptable}{}
    {\starttable [|c|]
     \NC \math{2} \VL\NR
     \stoptable}{}
  \stopcombination
\stoptext

It works without the combination, without the vertical or horizontal
rule and when no math mode is used. It used to work some time ago,
so I assume it's a bug.

Marco