If the decimal tabs are not aligning even though the screen looks OK and all techniques have been followed for aligning decimal tabs, you might need to look at whether you are using an Hewlett Packard Deskwriter. If so, make sure their HP Fonts are installed in the correct folder in the system folder. (The HP Fonts belong in the HP Folder in the Preferences folder. Restart and rebuild desktop and all should be well.)
This issue is especially pronounced when aligning three decimal tabs underneath each other with the middle section underlined. Hewlett Packard tech support says printing with True Type Fonts does not perform well when underlining is used.