It works for me. Using hidecmd from a shortcut to start LyX I have no flashing cmd window and LyX starts normally.
I tried your version, mine, and the merged one. All of them hide lyx. I use winxp sp2, what do you use? Anyway, I guess it is time to hand this to Uwe/Joost and let them try this with the installer. Lars, if there is no objection, I will add this to the trunk tomorrow (with #ifdef MSVC suggested by Angus). Bo