Dear all, When typesetting an old list of exercises, I noticed that when \showgrid is active and a luafunction is called, there is some unwanted and strange background colors (gray and blue, or yellow and blue). Thes background colors seems to show up on an unfilled page when a lua function is used, and I could come up with the following minimal example which gives the attached PDF. Could someone, please, tell me what I am doing wrong? Best regards: OK %%%% begin test-strange.tex \showgrid %\setuplayout[grid=yes] \startluacode AdditionTest = function(nn) local a = {} local b = {} for i = 1,nn do a[i] = i b[i] = nn - i end context.midaligned("\\bfa Exercises") context.blank() context.startcolumns { n = 3 } context.starttabulate { "|r|c|r|c|r|" } for i=1,nn do context.NC() context(a[i]) context.NC() context.mathematics("*") context.NC() context(b[i]) context.NC() context("=") context.NR() end context.stoptabulate() context.stopcolumns() context.page() end \stopluacode \starttext \ctxlua{AdditionTest(12)} % the background colors, gray and blue, show up when a lua function is called % \ctxlua{AdditionTest(120)} % the background colors, yellow and blue, show up when a lua function is called % \input knuth % the background colors do not show up here \stoptext %%%% end test-strange.tex