The 2007 version uses SOAP to access the server. Although this facilitates clients over low bandwidth / high latency connections, it adds a level of complexity (in the form of a Queue) that must be managed by an administrator. Specifically, a job in the queue could get stuck and block other jobs from completion. The advantage of the queue is that MS Project uses a local cache, enabling the user to continue to work on his project plan even when he is not connected to the server.