First thing i would check is if indeed there is a data difference between the two environments, aka the upgrade malfunctioned somehow on the live and the data is not working properly, perhaps you didn't run the site when you went to version 10 and let it finish it's tasks before going to 11.
Another possibility is sometimes when the database tables change, the Views don't update properly right away and need to be refreshed, this can be done in the Database Objects, you can try refreshing them all and see if maybe there was some caching going on of the views.
Any Event Log Errors?