Originally Posted by SEOBook.com

Google Algorithm Shift:

Google did an update in early February which caused many sites to
no longer rank for their official site names.

Some have stated that they thought Latent Semantic Indexing was
used on links while others still believe it is technically
impossible. Whether or not they did that I still think it is
important to understand the general concept of LSI and what
it does.

A few common problems amongst sites which fell were: inadequatley
mixed anchor text, low deep link ratios (few other sites linking
into their deeper pages relative to the # of links pointing at
the home page), and many sitewide inbound links.

This was also seen more often on sites where their official
names were well aligned with their keywords, as that also
consolidates anchor text variations.