Print button gray out in Outlook

Print button on the tool bar is missing when I double click and open a message. Sometimes Print/Print Preview option in File menu is grayed out too. I can print without opening the e-mail. I can bring the Print button back up by resetting the tool bar, but doesn’t fix in the file menu. This problem occurs in both Outlook 98 & 2000. Why is this happening and how can we fix it?