oscommerce paypal IPN fix

I have a live oscommerce store, and I am experiencing the following problems: 1) when someone from the US (with a US paypal) checkous out successfully, the store receives IPN notification from Paypal and changes order status accordingly, but when someone from outside the US checks out successfully, IPN is not received, and I have to manually go verify the payment. IPN needs to be fixed so that it works properly - ON A LIVE SITE 2) Because of the nature of my business, I have oscommerce setup to save the order as Pending as soon as the client leaves the site to go to Paypal. The problem with this setup is that if the customer clicks "back" from paypal (or loses connection and comes back to place the order again), they cannot place the same order again as there is already an identical order Pending for them, but they cannot access this Pending order either - the only solution is for them to make a different order, or for me to delete the Pending order. A new solution for this needs to be discussed and implemented (probably as simple as allowing duplicate orders, or creating a way for customers to access and pay for Pending orders that the (now fixed) IPN hasn't changed the status of). 3) The above must, of course, no break anything previously installed / modified / customized in the store. Requirements: -=- Extensive VERIFIABLE oscommerce knowledge (store is very modified and the code is quite messy) -=- Fluent English (if you can't spell-check your bid, I can't trust your work) -=- MSN Messenger (non-negotiable) -=- Reasonable timeframe -=- Payment by escrow, to be released once everything is installed and has been live for at least 5 days for testing purposes. -=- Must write "yeah, I get it" in the bid to confirm having read all this -=- I would much prefer one person that knows what he/she's doing than "a team of professional coders" that have to refer to manuals