I agree with the last post. You must be doing inserts, updates, deletes, somewhere in order to get deadlocks.

Are you possibly creating global temporary tables as part of the querying and then inserting, updating data there? That could lead to deadlocks.

However, you could try, since this is a reporting database, setting the database to be read only. Then you shouldn't see any kind of locking at all, including shared locks. You should also get a performance increase because of that.