Office 2008 installs new fonts. Did you restart your computer and run Repair
Permissions?
I also recently installed office 2008 on my mac and my safari text was
messed up. Through trial and error one of these things fixed it.
1. at the top left click safari and click reset safari
2. Click safari at top left, click prefs. go to appearence, make sure
your standard font is times new roman 11, your fixed width font is
times 13, display images when.... is clicked, and default encoding is
western(mac os roman)
those were the two that i did, i'm not sure which one worked for me,
but also if you have any question about it
http://discussions.apple.com/category.jspa?categoryID=169
this is a forum for all mac programs, the link i'm giving you directs
you to the safari section.
Hope i helped