I have customized the magento's price rounding by changing in app/code/local/Mage/Core/Model/Store.php file's Round function and set the precision to 4 instead of 2 and also do changes in app/code/local/Mage/Paypal/Model/Api/Abstract.php for _exportLineItems function's $request[sprintf($privateFormat, $i)] = $value; line to $request[round($privateFormat,2)] = $value;
After this everything is working fine. But Now I have got an issue, When open paypal account and then via activity open the order for payment details it shows me different amount.
And this one is from paypal, Here you can see the amount is different from my store :
One more thing my store has 7% tax and all products are incl. of tax.
Suggest where to changes to get the same amount details in paypal account.