Why are fonts fuzzy?

[johnu]

When I view source code of a web page in Firefox, the font (Courier New) is clean and crisp. When I view the same source code in TextPad, in the same font, it's fuzzy and harder to read.

This happens with a Compaq Q2159 wide-screen monitor.

1. Is there a reason for it.
2. Is there a work-around?

ps: here are snapshots that illustrate the difference:

TextPad: http://www.john-uebersax.com/bin/textpad.jpg
Firefox: http://www.john-uebersax.com/bin/firefox.jpg