missing characters in printed copy

[mar.s.i.]

i created a mail merge document.
just plain text with one single image(signature on letter).

after completing/printing the job. we just realized that some characters are
missing
within the body of the letter.

i cant figure out what seems to be or root of the problem.
i tried to save the same exact document to previous version..(97-2003)
and then tried to print a couple of sheets....it looks perfect.

can somebody gave me info what may have caused that problem?

here's some additional info:
o.s. xp
word 2007
printer : canon ir110 using pcl driver
note: used the same flatform and driver to print the older version of word
doc.
which gave me a perfect output.

im trying to figure this out after i screw up a couple of thousands worth of
job
and help us to avoid the same error in the future...
thanks again for any info or ideas regarding this matter.