Here is something else I notice since Penguin on a site I own which has never been positioned well and probably running a penality.
1. do a search & click page 5, 6 or 7 - my site does not show
2. go to page 8, then click back to page 5, 6 or 7 my site shows.
Is this another type of penality only showing if you back track or for every other search?
Anyone else see this?