Ganthead offers a useful piece on "Practical Outsourcing Control." (You’ll have to register for free to read it.) The theme is "common difficulties" and how to prevent them.
For example, here’s a situation recounted in the article:
The outsourced group may have their own process that they are proud of. A project manager I know was once frustrated by an outsourced group in India, which was to accept design documents from one of her teams and complete programming. The outsourced group’s process included a step to check all incoming design documents and create a report of every single discrepancy, then send the report to the client. Her representative proudly forwarded the report to her. She was not amused. This was a day of work lost in a very tight schedule in her view, a day when programming should have–and could have–begun.
I’ll let you read the story to get the solution.