After a reader posted this item to our message boards (claiming a defective strap had cut her child), we asked Peg Perego if in fact there was a problem with their Primo Viaggio infant car seat. 

Here is their reply:

Over the past few months, Peg Perego learned of a few incidents where infants have received scratches and minor bleeding to their lower legs while sitting in a Primo Viaggio 30-30 car seat. We have not heard of any instances where professional medical care was required.  
 
We immediately inspected all of the car seats in inventory and discovered that on some Primo Viaggio 30-30 seats, the interior edge of the plastic adjuster strap cover had minor excess flashing (a molding situation where excess plastic leaks from the mold and creates an unintended edge on the component). Our inspectors did not find any seats where the flash was sharp enough to fail the “sharp edge” safety test procedure. We immediately revised the mold to eliminate this problem.
 
NHTSA has been notified about the problem and Peg Perego is working with them for a formal/legal solution to resolve it.
 
We have also undertaken an informal solution by providing our consumers with an immediate solution for this problem.  We have provided this information to bloggers and we will place this Customer Notification information on our web site:
 

Replacement part available for Primo Viaggio SIP 30/30

A new adjuster cover has been sent to all consumers who have registered their Peg Perego Primo Viaggio SIP 30/30 car seat, manufactured between July 2007 and March 2008.                                   

Peg Perego has sent and will continue to send a new improved adjuster cover to any consumer calling about this problem                                                              

 Toll-Free number to call:  1-800-671-1701.

We have taken this voluntary action because a mold flash, creating a rough edge, may exist on some of the car seat adjuster covers manufactured between July 2007 and March 2008.

The part in question has scratched the heels of a very small percentage (less than π of 1%) of babies who were not wearing socks. In all reports, the scratches were minor and did not need professional medical attention.

Peg Perego takes each and every concern seriously, and responds proactively to help keep your baby as safe and secure as possible. 
Update: We also asked Perego about the parent's allegations that the seat accidently detached from the stroller. Here is their response:
We’ve had very few instances where consumers reported that their Primo Viaggio car seat became unintentionally detached from and fell out of the stroller. 
All of these reports were investigated; we’ve had some of the products returned to us where we inspected them in our certified safety lab and we statistically sampled and inspected identical products from the same production batch. We have never been able to duplicate an unintentional detachment, when the car seat was installed according to the instructions. We advise consumers that after they attach the car seat in the stroller, they should lift up on the car seat handle to insure that it is attached. We are in the process of rewriting this instruction to be so that it will not be overlooked.