Paypal IPN not getting orders in ZC, no error msgs in logs

---** background info **----
ZC 1.3.8a (fresh install last year)
Added - Googlecheckout (Paypal IPN worked successfully after Google Checkout was installed)
Customizations - customized for layout and images through language files
I do not think this is a hosting issue, as nothing has been changed with the host and this was working a couple of months ago.
Not sure how long it has been down - I do not get many sales through my online store. First failure was seen yesterday. I have not been able to get it to work properly since I recognized the problem.

Using Paypal Website Payments standard (IPN)
Symptom: Paypal payment notification is received via email, but the store shows no sign of the order (customer info is there).

I turned on debugging for Paypal IPN. I then tried placed several orders (paying with a second paypal account). It appears that Paypal is continuing to send and resend the notifications of the sales and subsequent refunds back to my store, but for some reason they are not being processed.

After making payment in Paypal, buyer is never returned to the store. Browser says it is trying to load the page from the server, but it never responds. After several minutes, a blank page is displayed.

Attached are sample log files (I removed some personal info but the relevant stuff is untouched) from the /includes/modules/payment/paypal/logs folder. If there is a way to get more detail in these log files, please enlighten me on how to do that.

Thanks in advance!

Start with the easy attempt at a fix - -

In your admin, first note all your ipn settings, uninstall ipn...

Re-install IPN and test again

I've tried that already. No change.

OK, I reinstalled the payment module again, and still there is no change in the behavior. What am I missing??
Obviously, something is wrong. I checked the DB, and I see the "zenid" values from the debug messages in paypal_session.session_id.
There must be some way to get more debugging information to find out what is going wrong...

Anyone have any ideas on this???

The logs show receiving IPN notifications from PayPal, but do not show any response coming back when attempting to send the data back to PayPal for a validation check.
This could be a result of a PHP error, or a firewall block from sending data from your server to PayPal, or a fsockopen block by your hosting company's PHP configuration, or a problem caused by conflicting addons, or any number of things.

Suggested approach:

1. Try the PayPal troubleshooting tips: http://www.zen-cart.com/wiki/index.php/PayPal
2. Compare ALL your site files against the original files, and find out what's different and why. Then reconcile any differences as required: http://www.zen-cart.com/wiki/index.php/Troubleshoot_-_Diagnosing_Obscure_Issues

Thanks. Unfortunately, I've already tried both of these to no avail.

I'll contact support for the hosting company and see if they have changed anything.

maffud:

Thanks. Unfortunately, I've already tried both of these to no avail.
Really?

Okay, so when you followed the troubleshooting steps and ran the ipncheck script, what was the output?

I did not see any change when I installed the debug tool. No error log files are showing up.
Access to the cache folder shows as "777". However, there is an .htaccess file in that folder. I wonder if it is not correct or maybe it should not be there at all. I am not a unix/linux guy, so I really don't know how to read or set up the .htaccess files. I don't remember if it was always there. It is possible that I put it there after reading about how to make the site more secure.

Contents of cache .htaccess file:

#prevent directory browsing -- for security
IndexIgnore */*

<Limit GET POST PUT>
Order Allow,Deny
Deny from All
</Limit>

I removed the .htaccess file from the cache folder, and still I am not seeing any log files generated in that folder.

Also, I checked the error log for the site in my hosting control panel, and it is completely empty. I don't know the scope of that log, but I couldn't find any other log options that might show internal errors.

I wasn't referring to installing a debug tool, or dealing with cache folders or .htaccess files. They're unrelated to this matter at present.

I suggest you go back and actually read the articles I referenced, and follow the suggestions there.

Sorry - missed that particular tool - three pages deep in one of the files you indirectly mentioned. So sorry to disturb your delicate genius with my trivial issues. Nice attitude, by the way.

In case it matters to anyone else, I got a timeout error running the IPNCheck script. The timeout occurs on the fsockopen statement. I just found that I am also getting a timeout error on an fsockopen statement in another (non-Zen) site on the same server, and that is not when trying to connect to Paypal. I think it that case it may be trying to hit the USPS site for postage information. So I am opening a ticket with the hosting company to see why the outgoing communications are not working.
I think they recently upgraded the server software (Apache), so maybe some default settings were changed.

maffud:

Nice attitude, by the way.
Sorry that you thought my attitude was bad ... what else was I supposed to say? I already told you the cause of the problem and pointed you to the tools you'd need to use to verify the problem was in sending responses back to PayPal. The fsockopen timeout that the ipncheck script showed you is exactly the proof you needed in order to confirm that your hosting configuration is the cause of the problem you have.
Glad you've found the root cause. Hopefully your hosting company will fix the problem easily for you.