pp_express problem with product prices over 1000

[bmett]

The Paypal Express payment module throws an error when one (or more) products in the cart have a price over 1000.
Reason for this is the number_format call in /catalog/model/payment/pp_express in the paymentRequestInfo() function. On line 182 number_format is called without defining the thousands delimiter which defaults to a comma. Product prices over 1000 will therefore be formatted like this: 1,000.00
This causes the addition of the $item_total variable to interprete the price as 0.
$item_total will end up being different to the sum of all product prices paypal calculates and that will cause paypal to throw back an error.
Can be fixed by either telling number_format to use an empty string as the thousands delimiter or by using (float) on the price.