I work as a Product Owner in a small IT firm. We have been doing Scrum for several months now. We do not follow Scrum by the book, but rather improvise Scrum implementation as per our needs. We have a product backlog, conduct sprint planning sessions, execute the sprint, etc... i.e. we follow Scrum procedures and events. However, we don't estimate the stories during sprint planning sessions, and select the product backlog items based upon our judgements and assumptions as to how many stories we can complete in the sprint. Even though the process is not perfect, it works just fine for us.
My main issue is that the Chief Project Manager demands to see and verify the product backlog before each sprint begins. He keeps pressing us to deliver more productivity, and as a result, some of the sprints have been remaining incomplete in the recent times. Moreover, he makes it a point to attend each Scrum meeting and start issuing instructions to the team. He is a senior person and we are at a loss how to go about resolving this issue.