WP hyperlink color display errors in IE – CSS related?

http://www.greenlaw.org.cn/blog is the WordPress site that I’ve customizing at the moment. I have little experience with HTML/CSS but have picked up a lot in the last few weeks. The theme design is something I’ve taken over from a previous developer who proved incompetent at finishing things on time. In these last two weeks I’ve fixed up all the small errors and content that they never implemented.

The site now works fine in Firefox, but it is displaying strangely in IE. Notably, some hyperlinks for the posts (i.e. category links, tags, etc) are coming up as white on white background if they are unvisited links.

This may have something to do with the CSS code that the previous developer inserted to make the hyperlinks in the sidebar white. Last week, I noticed that the job was incomplete for some widgets, so I inserted a bit of code as well to define hyperlinks for the text widget as white.

The site is pretty much close to launching with the sole exception of this one error. I’ve validated the site with a CSS checker and it is definitely picking up on this error; I’m just not sure how to fix it. We’re aiming for a Friday launch date, so any technical advice would be great!