Printing .rtf files

I have several users at work who cannot print .rtf files. I have looked all over the web and cannot find an answer to this problem. Some users can print .rtf files just by clicking print, others have to re-save the document as a .doc file and yet others cannot print at all. Everyone uses Office 07 and Windows Xp Pro, on Dell desktops or laptops. What is going on and is there any way to fix this?