I'm hoping someone can help me. I'm setting up Zen Cart for the first time (one of the best I've seen) but am having problems integrating Paypal IPN.

- I'm using ZC 1.3.8a.
- I'm on a Godaddy shared hosting server and called to confirm part 80/443 are open.
- I've checked the setup three times with Paypal and in Zen Cart.
- When I do a test check out of my test product at $.01, paypal transfers the fee between accounts correctly but the Auto Return URL opens to a blank page (but it is the correct URL with some appended parameters)

Here are the errors I see in the log file:
Mar 29 2009 20:46 -- IPN INFO - POST VARS to be sent back for validation:
To: http://proxy.shr.secureserver.net:3128
POST http://www.paypal.com/cgi-bin/webscr HTTP/1.1

Host: proxy.shr.secureserver.net

Content-type: application/x-www-form-urlencoded

Content-length: 101

Connection: close



Array
(
[cmd] => _notify-sync
[tx] => 6BH06124K34229439
[at] => zzJoz**********K2beC
)


Mar 29 2009 20:46 -- IPN FATAL ERROR :: Could not establish fsockopen.
Host Details = http://proxy.shr.secureserver.net:3128 (-1221824180) Unable to find the socket transport "http" - did you forget to enable it when you configured PHP?

http://www.paypal.com/cgi-bin/webscr
Trying again without SSL ...

Mar 29 2009 20:46 -- IPN FATAL ERROR :: Could not establish fsockopen.
Host Details = http://proxy.shr.secureserver.net:80 (-1221823772) Unable to find the socket transport "http" - did you forget to enable it when you configured PHP?

http://www.paypal.com/cgi-bin/webscr
Trying again without specified protocol ...

Mar 29 2009 20:46 -- IPN FATAL ERROR :: Could not establish fsockopen.
Host Details = proxy.shr.secureserver.net:80 (111) Connection refused

www.paypal.com/cgi-bin/webscr


What is the likely problem?