I have a grid which consistently receives zero in the ARCC as a parameter when I click on it. And it won't react to tabbing either.

Here are some properties, if that matters:

anchor=135
columncount=3
deletemark=.f.
enabled=.t.
gridlines=0
highlight=.t.
highlightrow=.t.
highlightstyle=.t.
lockcolumns=0
optimize=.f.
panel=1
readonly=.t. (tried with .f., same)
recordmark=.f.
scrollbars=2
tabstop=.f.

The recordsource is a readwrite cursor, indexed on each column into a temp cdx.

What could cause such a situation? I've never encountered a grid which wouldn't pass a proper columnOrder (which is not zero for any column, checked that too) to ARCC.