sGroup - 3:15 pm on May 30, 2010 (gmt 0)
We manage an ecommerce site (not affiliate site) that is 3rd largest in its vertical.
80%+ of our links to this ecommerce site are from medium quality sites in terms of home page PR(PR0-PR4).
My guess is our links are on pages that have either lost live PR, not currently in the G index. Basically either have lost PR or filtered out by this current update.
We used to be in position #2/3 and now we are at #10/11.
We continue to acquire links and do not plan to stop what had worked for 9+ years on G.