Having chatted to Simon previously about this lash up, it's a really horrible nasty mess. Bascialy they have an Access client using linked tables to talk to a SQL server. The queries are not only stored client side, but because Access doesn't know about the SQL server, they are exectuted client side as well. i.e. Access downloads the whole damn table then works it out for itself, rather than passing the query up to the SQL server. That isn't by any design, simply how Access linked tables work if you don't tell it otherwise. Even worse when you bind a form to the linked table, access will leave cursors in the SQL table while the user is inputing data, same as it would do with an Access back end.

If you know anything about databases you'll be screaming and trying to claw your eyes out at this point. It's probably a worse solution than just using an Access backend. The performance is about the same (all the data gets dumped to the client for processing either way), but unlike an Access backend, SQL server will actualy try and do locking and other such things to manage the horrible mess Access will inflict upon it.

Makes me weep to think of it.