Paypal IPN issue after upgrade

I recently upgraded one of my sites from 1.2.5 (I think) to 1.3.7.1 and I am having an issue with paypal ipn. Orders will go out to pay pal (with the correct dollar amount) but the never show up in admin. An order email is never generated to the customer.

In addition while I was testing I noticed when I returned from paypal the final screen always gave me the same order number (it was an old order number of mine that I used to test the checks)

I installed Dr Bytes paypal session viewer and it errors out with this error --
Catchable fatal error: Object of class shoppingCart could not be converted to string in /admin/view_stuck_paypal_orders.php on line 71

So I am guessing something, presumably in the database got messed up in my upgrade. Can anyone point me to a fix or at least help me figure this out. I know enough to be dangerous (well not quite that bad :) )

Thanks

BeerCan:

Orders will go out to pay pal (with the correct dollar amount) but the never show up in admin. An order email is never generated to the customer.This indicates that PayPal's server isn't communicating with yours in order to let your store know that payment is completed.

BeerCan:

In addition while I was testing I noticed when I returned from paypal the final screen always gave me the same order number (it was an old order number of mine that I used to test the checks)This is another symptom of the same problem.

BeerCan:

I installed ... paypal session viewer and it errors out with this error --
Catchable fatal error: Object of class shoppingCart could not be converted to stringThat's a PHP5 quirk. A fix was posted somewhere for it ... I forget where just now.

BeerCan:

So I am guessing something, presumably in the database got messed up in my upgrade.I'm not so inclined to suspect your database as I am your PayPal and communications settings.

PayPal FAQ: http://www.zen-cart.com/wiki/index.php/PayPal
PayPal debug logging: http://www.zen-cart.com/forum/showthread.php?t=61199
PayPal communication testing tool (basic): http://www.zen-cart.com/forum/showthread.php?t=65680

Dr Byte thanks for the reply. I used the test tools to do some checking and all the results were good. Strangely when I did a test transaction so I could get some logfile info everything worked fine. So I guess I had some glitch somewhere that worked itself out. I do appreciate the links for the diag tools, now I have them for future reference.

Maybe you were just testing on a bad day at PayPal.
http://www.pdncommunity.com/blog?blog.id=mts_updates