The IE users who are setting the font size to minimum are confused.
Because the font size of titles (h2 anchors) are smaller than that of other descriptions in the result pages of web search.

View a source of result pages:
[embeded css]
.sl,.r{font-weight:normal;margin:0;display:inline}
.sl{font-size:84%}
.r{font-size:1em}
[html]
<h2 class=r><a class=l ...

The font size of class "r" should be modified:
[from]
.r{font-size:1em}
[to (e.g.)]
.r{font-size:100%}

And, class "l" (attribute of the anchors) is not defined in the stylesheets (that should be confirmed).
--

I hope many google users report the above suggestion to the Google Help Center:

Google: Web Search Help Center
http://www.google.com/support/bin/request.py?contact_type=search
http://www.google.com/support/bin/request.py?contact_type=cf_noresponse