You could try "round-tripping" the file to see if that helps:

HTML "Round-tripping" to repair corruption
http://www.pptfaq.com/FAQ00526.htm

The times (pun unintentional but unexpurgated regardless) I've seen this, the
only thing that helped was re-making the slide from scratch.

-----------------------------------------
Steve Rindsberg, PPT MVP
PPT FAQ:  www.pptfaq.com
PPTools:  www.pptools.com
================================================

Hi there

A couple of thoughts:

1. Make sure you have a local colour printer driver installed (even if you
have no printer) and set as default:
How to install a local printer driver
http://pptfaq.com/FAQ00605.htm
How to select a default printer
http://pptfaq.com/FAQ00131.htm

2. What font is the presentation trying to use? It may be it is replacing an
unkown font with Arial on screen but Times New Roman in print (I thought it
replaced serifs with TNR and sans-serifs with Arial ut I'm so often wrong).
Check Format -> Replace Fonts -> are there any fonts with a ? next to them in
the top box? If so replace with Arial and see if this helps. Oh, if you use
2007 you'll find that on the Home tab in the Editing box -> Replace drop down
arrow -> Replace fonts.

Lucy