Hi,
Sometimes this is due to the size setting and the particular printer. The staff lines are quite thin, and if the size is set on the smallish size (eg. font size 9 or smaller), sometimes the way the printer "lines up" the horizontal "slices" of the score can cause it not to print the staff lines correctly. Please try printing it out using a slightly larger font and see if this corrects the problem. Alternatively, you can post a copy of the file, or send it to us at
support@notation.com and we can take a look at it.
ttfn,
Sherry