I have comeaccross this several times, usually when the report has several memo fields that are full of long 'essays'.
I am not sure how you are exporting the data, presumably from a report. Presumably you create an RTF file which is then opened up in Word or you use the Publish with Microsoft Word button on the Report toolbar?
The way you design your report in Access seems to help (or hinder) the process. Make sure your field widths in your Access report are set to a width that is equivalent to the full width of the page in Word. If that doesn't help things please let me know and I will try and think of something elese.
(I will be off-line tomorrow but I will check the progress of this posting on Thursday.)