When printing from Lightroom, the program edits the picture's file name. E.g. if the file is called "IMG_1337", Lightroom will by default name it "Lightroom (IMG_1337)" when it's sent to the printer. This poses a problem when printing from Lightroom directly to a MiniLab, as the backprint becomes too long - thus making it impossible to fit the entire file name on the back of pictures (backprint will only print aprox. 10 characters). Disable this and just leave the file name as is.