A WebmasterWorld thread reports that Yahoo!'s cache is mishandling the <SUP> </SUP> (superscript) HTML tag. The superscript tag basically looks like this, often used for adding comments1 numbers for reference or other characters to words.
Yahoo! Moderator, jdMorgan, confirmed this as an issue;
In your case it was the </sup> closing tag that got changed to HTML character-entities. In my case, it was the opening <sup> tag. Because of this difference in our applications, it looks like a problem handling <sup>s nested within other tags.So that's a confirmation of what appears to be a fairly straightforward bug.
Forum discussion at WebmasterWorld.

Comments:
Robzilla
12/14/2006 04:03 pm
<a href="http://i16.photobucket.com/albums/b25/rduketc/ser.gif" rel="nofollow">Look</a> what you're doing to my Google homepage ;-)
Barry Schwartz
12/14/2006 04:09 pm
That was my fault actually...
David Ogletree
12/16/2006 06:44 pm
yeah thinks for screwing up my google home page.