I am printing from a word processing program, and what is printed is different from what appears on the screen.
Make sure that Include PostScript and ChemDraw LaserPrep options are on in the Preferences dialog box in ChemDraw before copying and pasting. Sometimes resizing structures within the word processing application will cause it to lose PostScript and LaserPrep. If you need to resize, scale the object within ChemDraw. If using MS Word, make sure that fractional character widths is on in the Page Setup of MS Word and in ChemDraw. Other suggestions are to try a different printer, try a different laserdriver (this can be changed from the Chooser in the Apple menu), try initializing the printer, or try recycling the printer (turning it off and on).