According to
http://www.xxxlaw.net on the 2257 table (click whats new then click the table link):
"Producer does not include....A provider of Web-hosting services who does not manage the content of the computer site or service"
So my interpretation is that hosting in the USA is irrelevant, its only where the primary and secondary producers of content live that matters.
Therefore, it only matters where your main business activities are conducted...so if you have a non-US presence + use non-US based processing then you do not have to stress over this even if you are physically hosted in the USA!
cheers,
Luke