Pathfinder not working correctly

Text that I have coverted to paths ist siupposed to subtracted from a butto so the background will shine through.  It works  on most of the letters and numbers, but something wierd happens and not alle of the paths are subtracted correctly showing the background of the button in part of the text where it should be transparent, but the entire path still exists as a path.  It happens in illustrator as well as InDesign und the Font Type does not matter either.