I got that too and noticed the typo in their sample PHP code for the Host: header. Even after correcting the typo for the new HTTP 1.1 request, I'm finding my

I got that too and noticed the typo in their sample PHP code for the Host: header. Even after correcting the typo for the new HTTP 1.1 request, I'm finding my postback verification is being hung up for a long time before I get a VERIFIED response, during which time Paypal sends me duplicate IPN notifications. I'm switching back to HTTP/1.0 requests for now since it worked just fine before and I don't have time to debug this right now.... thanks Paypal...