Not sure if this has been discussed before, but I noticed Google is converting HTML entities before processing the query. MSN and Yahoo strip the escaping characters before processing, so they return different results compared to Google for the same HTML entity query.

Full post is over at my blog (http://www.socialpatterns.com/search-engine-marketing/google-msn-yahoo-treat-html-character-entities-differently/), but test out how the engines process HTML entity searches to see the differences.