Here it is straight from the horse's mouth:
This is a follow-up to the bulletin we sent on September 12. It has come to our attention that some merchants may have received emails where the sample code snippets had syntax errors. We would like to apologize for the inconvenience and make sure we publish the corrected code snippets. Additionally, some merchants reported that their IPN scripts updated to use HTTP 1.1 get "hung" or take a long time to get a ‘VERIFIED’ response. We are including instructions on how to remedy this issue as well by adding "Connection: close” header in the HTTP request.
I forgot to mention that PayPal's PHP example also had a number of syntax errors.