Dear Mojca, As you told me, I changed "outputdriver" in tex.rb from xdvipdfmx to xdv2pdf and run it. There is no delay at all, but the output pdf lost color and mp stuffs. I think that it is better to use xdvipdfmx even though it took more times. During the test, I found a strange result. Here is the last part of the log file. %%%%%%%%%%% systems : no file 'cont-sys.tex', using 'cont-sys.rme' instead ) ) [7][8][9] <--- at this point, TeXniscope redisplay the pdf file in which backgroundscreen or backgroundcolor is well applied 81117 bytes written Output written on combimain.pdf (9 pages). Transcript written on combimain.log. TeXUtil | parsing file combimain.tui TeXUtil | shortcuts : 169 TeXUtil | expansions: 308 TeXUtil | reductions: 0 TeXUtil | divisions : 0 TeXUtil | loaded files: 1 TeXUtil | temporary files: 0 TeXUtil | commands: 42 TeXUtil | programs: 0 TeXUtil | tuo file saved At this point, it paused for long time ** NOTICE: This document contains a `Preview & Print only' licensed font ** TeXExec | runtime: 144.462654 At this point, TeXniscope redisplay the output again and in which backgroundscreen and backgroundcolor didn't work. %%%%%%%%%%%%%%%% Do you have experienced the similar thing? Thank you. Best regards, Dalyoung