Dear Kim :
Note that the default pen width is 0.039 inches, so perhaps your printer / plotter driver is interpreting some of the lines as being too thin to output.
You can adjust the line width in the Print dialog box. Select "Configure...". Once you have the printer settings to where you want them, you can then save these settings and reload them for other drawings.
If you have any additional questions or need any further information, please contact me again.
Sincerely,
Chris E. Maeder, M.S.
Senior Technical Engineer
chris.maeder@bossintl.com