Are your internal controls really effective?

Some companies find themself in a dilemma. They implement an internal control structure that they believe will effectively ensure that they are protected against fraud and errors being introduced into their business processes. In many cases these internal controls do the job - in other cases though a company becomes too reliant on internal controls and will be ill-prepared to see beyond their comforable process framework. Are you planning and managing to ensure you will catch all potential issues?