"Overriding inherited .tpl.php templates: Add a template file with the same name in your sub-theme folder to have it override the template from the parent theme." on drupal.org
Made subthemes with base Omega / Framework and more for testing if anything showed. Then I checked whether regions are shown in Blocks with modifying info file and they appeared just fine. Then when I copied page.tpl.php into subtheme's templates folder, I tested by putting dummy text in page.tpl.php and see if text showed up. It didn't. I tried every base theme with sub theme but nothing changed by modifying template file in subtheme's template folder.
I even drush cc drush a few times, but nothing shows up.
I am not sure why it is not working for subtheme with any base theme :(
I had to uninstall Drupal and drop database. I redo install drupal with fresh database. Then tested overriding a few theme bases with a few subthemes. it worked charm.