BeeDeeDubbleU - 6:13 am on Sep 6, 2012 (gmt 0)
My guess is that maybe Penguin is all about external links.
My experience is that it is not.
I had four sites that were affected and only one of these just possibly could have been attributed to external linking problems. I think it may have been as much about internal links (over optimisation) than anything else. All I know is that there are no signs of recovery despite several attempts at remedial work.