suddenly paypal transactions do not show?

I have had no problem for 2+ years and now suddenly i have this problem: when people pay using paypal, the transaction does not show in zencart (1.3.8a)?

It appears that this occurs intermittantly. Some show but others don't?

I turned on paypal log. When I checked includes/modules/payment/paypal/logs, i do not see anything even on the same day the transaction occurred?

I am not sure if this is a zen cart issue or my server (Linux Ubuntu) problem? if it's the server, what's the possible problems?

Thanks for helping.

Suggest that you subscribe to this area

This is a PayPal issue and also suggest that you do 2 things

Upgrade before you are hacked

Use the PayPal Express method versus IPN

http://www.zen-cart.com/forum/showthread.php?t=177771

actually, i have been using paypal express checkout. and i am unable to post in the mentioned thread..

i am unable to post in the mentioned thread..
That thread is only an announcement and not for assistance...

This is the location to receive assistance

You might need to narrow this down to a specific period - the smaller the better and have your host look at the php logs for a clue

Or better yet, perform some test transactions and see if you can replicate the issue - - you need some Pay Pal account other than the one the cart uses as you can not purchase from yourself

Keep track and when one does not show up note the time for your host to seek any errors

actually i did test transaction and it worked! so the problem is intermittent...

Issue been reported few times, no solution came about yet. The Zen Cart team claims it might be some other module causing the issue.

I had the same issue and still have issues with PayPal so I went back to IPN "It works sometimes"