Paypal付款标准订单数据在付款成功时无法收到

I upgrade mageto version 1.5 to 1.9.
In that when i do payment with paypal standard than payment successfully complete but order status 'Payment Pending' Display.
And in Order detail not get any paypal payment transaction detail.
Help me for that.
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Some times it will become completed in 2-3 days once it receives more details from customer. Paypal will generate IPN again. search for reason_code below for possible reasons for pending:

https://developer.paypal.com/webapps/developer/docs/classic/ipn/integration-guide/IPNandPDTVariables/#id08CTB0S055Z