Adam thanks for the contrib. I am working with a client right now and trying to debug this contrib on his osCommerce sites. From reading through here is looks like others have had the same problems, ie the automatic set up doesn't work. I manually installed all the MySQL tables and still the update wouldn't "take" from the config page. So I manually set it to "active" and got it to work but now it still won't download the IIF files.
My guess is that this is related to the "register_globals" being off on this host. I have v.2.10 of your contrib and see that you plan on fixing the "register_globals" issue in 3.0. Do you have a plan date for this to be done? Also if you need / want help with this drop me an email and I might be able to put some time into it. Basically I am trying to decide if it would be easier to modify your contrib with a 'one-off' fix or rebuild php on a remote server.
Thanks again,
Matt Swaffer
Dynamic Dataworks LLC