>Sergey,
>
>The computer that has the error had an HP 870c driver installed under WinXP. The same driver was also installed on a Win98 machine. Works fine on the Win98 machine but on the WinXP the error persists. I changed the driver to HP 880c and the problem goes away. There is evidently a problem with the HP870c driver under WinXP.
>
>Many thanks for your suggestion.....
>

It was just a lucky guess. I'm glad it was helpfull.