Block appears above main content despite beeing put below main content in "content region"

I want to put block below main content but when I create a block and put it below Main Content in Blocks-Content Region, the block appears above main content.
I changed sidebar position to the right as per instructions here http://drupal.org/node/1701312, so maybe this is the reason blocks act not as intended?
I'm not sure is it just me or someone else experiencing the same problem? Could you please tell me how to fix it?

Thanks!