I have a feed updating from the suppliers website, but its not correct on my oscommerce. Its leaving out of stock items there, or not updating the price properly. I have this website that shows the correct amount of items whats in stock and whats not in stock. Your job would be to correct the feed to inlcude the right amount of items. as to the comparisson site that offers the feed correctly.
Also if you can do this, then i have more work to update google feed and shopmania feed