SDL_ttf displaying fonts in different sizes with same point size set

Has anyone run into this? I am using SDL_ttf to display a font. With the
same code the font displays one size on one system and much larger on another.

One possible clue is that if I use a program like MS-Word or PaintShop Pro to
draw the font at a given point size (32 for instance) it looks much larger
than if I use SDL_ttf to blit it on the screen using the showfont demo.

If anyone has seen this and fixed the problem I would appreciate a suggestion.