Set your font options:
In firefox go to
Tools
Options
Content Tab
I'm using XP SP2 with all updates completed. I noticed a change in Fonts in Firefox 1.0.7 about the same time I uninstalled Nortons SystemWorks 2004 and installed 2006 version (not sure if that's related). Certain parts of webpages appear in small script font, while other areas are normal block letters. The script font is difficult to read.
Thinking this was a Firefox problem, I uninstalled and re-installed, and I noticed the install text was not visible at all. I tried Internet Explorer and found that some pages won't display, even though the progress dialogue says it is downloading images. I noticed that nothing appears in the blue Title Bar at the top of either Firefox (next to the Fox icon) or IE (next to the blue E icon).
I used Norton's to scan for viruses and spyware, and nothing was found. Unfortunately I have not yet re-installed Go-Back, which saved my butt before.
I know I didn't change the browser settings, but don't doubt that some software installation may have done so. I have a gut feeling it is something in the Registry, but I'm scared to go there. Any suggestions? Ideas? Help? Commiseration?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic