Word 200 Repetition of the last line of a page printing a doc

[pallottino]

Using Word 2000 when I try to print a long document, sometimes, but not always, I find the last line of a page repeated as the first line of the following page!

Note that it doesn't appeare on the screen but only on the printed copy!

It's crazy and terrible but true!!

What can I do?

Thanks in advance for the answer...