ps2pdf creates a negative Image

[Glenn Sorge]

        I have been trying to convert some Postscript files to PDF.
The Postscript files are images no graphic commands or fonts. The
conversion works with out errors bu when I display the image the white
backround is white and the black image in white. The PS files display
fine.

        I have tried the conversion with ghostscript on two versions
of Linux, Tru64 unix and windows 2K with the same results. Anyone have
an idea of how to fix this problem?

Regards

        Glenn