[pdftex] Help! pdfTeX: Get black squares (cursors) in @example text

[John Blevin]

In pdfTeX, when I include an @example/@end example of some
source code, when the line is long (say, >70 chars) there
is an annoying black square character (like a solid cursor)
at the end of the line.  How to avoid them???

This is with:
    pdfTeX (Web2C 7.4.5) 3.14159-1.10b
    kpathsea version 3.4.5

Thanks!

- John