The pointer and the scroll bars look weird too, not just the text.
Probably means that either the screen is messed up, or the mini's display output is.
I would suggest testing the monitor on a different computer, and the mini with a different monitor. That should tell you what is messed up.
You can also try changing various settings in the monitor control panel, or maybe the menu of the display itself. That may fix things, but I doubt it.
Thanks for your response, Daniel. I should point out that the Dell screen image looks perfectly fine using this setup on the Mini booting into OS 10.4, or using programs in the Classic OS 9 emulation. I would think if there was a problem with the mini itself, it wouldn't produce a nice crisp image when booting into OS X, or working in the Classic environment, but maybe I'm wrong.
Also, the monitor has always displayed perfectly using my 2010 Mac Pro. Unfortunately, I have no other monitors to test.
I can try your suggestion of changing something like the resolution of the monitor from the OS X Display preferences, but once I boot into the OS 9 install disc, I would think those settings would be irrelevant. I'm not sure what I could possibly change on the monitor itself.
Any other ideas?