Check the commercial printing in tools, restart Publisher
After you restart Microsoft Office Publisher 2003, do not open your mail merge
publication.
2.On the New Publication task pane, click Blank Print Publication.
3.On the File menu, click Print.
4.In the Print dialog box, click Advanced Print Settings.
5.On the Separations tab, click to clear the Print Composite CMYK by default check
box.
6.Click OK to close the Advanced Print Settings dialog box.
7.Click Cancel to close the Print dialog box.
8.Open your mail merge publication, and then print your mail merge.
Do you have the Service Pack for Office 2003?
http://office.microsoft.com/en-us/officeupdate/default.aspx