Problem with text reformatting

[mdw]

I'm using OO Impress 1.1 on two (nearly) identical Red Hat 9 systems.
When I create a presentation on one of the systems, and then open it on the other, sometimes the text is reformatted -- as if the font were slightly wider on one system. As a result, some lines of text do not fit on the slide, and wrap around, possibly overlapping with images and other text.

Has anyone else seen this problem?
I am using TrueType fonts that I have installed myself, and made available to OpenOffice through xfs, by editing /etc/X11/fs/config.
The same exact font is being used on both machines.

Thanks!