I think you may be confused with how PowerCMS is implemented.
Sounds like you have followed the instructions correctly and have PowerCMS properly tied to your pages.
The way this works now...is that you need to go through PowerCMS to insert the content that should display on your pages. Then, the Developer Notes reference that is provided to you in PowerCMS after inserting will need to be added to the page you want that content to appear.
It does not read the page on your site for the content....you copy/create that content directly within PowerCMS.
After inserting content, and adding that reference to your page, you should see that content appear on the page.
Does this help? Or are you still having problems?