[support] Menu problems Drupal 7

When creating a content there is menu selector at the bottom that allows placement of the content into a selected menu. This menu selector provides only <--Main--> and is no guarantee that the choice will indeed display in the menu Drupal 6 provided selection of every menu on the system. What has changed? If I create a new menu, add the block to Left sidebar or Sidebar first it does not display. Flush cache in Drupal or drush is no help. What am I doing wrong? Thanks Roger