You’re making this much more complicated, or you’re having some serious issues at your end.
Make sure .htaccess is CHMOD so that it is writable by WP. I take it you have a page.php? In the pages section, write About as the title, select the template page or whatever it is called. Enter some text, and save. View the page. Does it display? If yes, well done. If no then continue:
copy the page.php file and open it in Notepad.
At the top add this:
<?php /*
Template Name: About
*/
?>
<?php include "header.php"; ?>
If the include is there already, just remove one of them.
I believe this is the part you need:
<?php if (have_posts()) : while (have_posts()) : the_post(); ?>
<?php the_content(); ?>
<?php endwhile; endif; ?>
Again this should be there, but hey, it might not be – I’ve never played with or ever used Kubrick.
I tend to have the basic layout of the page in the template file.
Save as about.php and upload it. Select the template for the About Page and view it. Does it work?
I question the ue of WYSI editors for playing with template files. I suggest you use Notepad or Wordpad. Dreamweaver is better for layout, design etc but not really for making templates, at least in my experience. They can add their own tags, which are either deprecated or custom, and in some cases over used or unrequired.
Keep it simple.