I concur with Terry on all counts. Specifically:

1. How the underscores are displayed depends on the font you've selected
as your monospace font. Replacing them with an image is ugly and will
never look remotely nice.

2. I will fix the stylesheet if you can give me an example CSS that will
have the same effect on modern browsers, and at the same time give a
good appearance on IE6.

3. Thanks for noting, fixed the typo in r66795.