in reply to Need help with http 1.1 headers

and they say it's because this script is sending http 1.0 headers and we need to send http 1.1 headers instead.

IIRC, every http 1.1 server should speak http 1.0 without any problems, so paypal is lame:)

Also, I would use some paypal module instead of reinventing it :) but thats just me