IPN is returning POST array as NULL

[dinudanial]

Hi

I have implemented Paypal IPN in one of my site and i tested with sandbox and in live too..

Its worked fine.

2 weeks back, i got a payment and i got the payment email which is written in notify url of my code.

But when i checked my database, its not updated in my datbase...(the amount is credited in my paypal account, but the database is not getting updated.)

So i tried to debug it and i found that, after payment the POST array which is returning from paypal is getting as Null / blank,  thats why my database is not getting updated...

I have used  post method and cmd field as cart like below

      $this->add_field('rm','2');          
      $this->add_field('cmd','_cart');
      $this->add_field('upload','1');       

If any one have idea about it, please help me..

Please

Thanks in advance