Things have changed in the new Moodle. Blocks can be docked and then undocked individually or as a group. You can understand where you are in moodle by following the breadcrumbs listed at the top of the page. Use those breadcrumbs instead of back buttons on your browser to get around much more assuedly.
A few more items for teacher page management here too.
Please see this Using and Learning Moodle page for more information and a tutorial video.