Upgrade from 5.5.2.1 to 5.6.0.2 breaks page formatting

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I am trying to incrementally upgrade on old site to version 5.6.3.2, but at the first upgrade from 5.5.2.1 to 5.6.0.2 my page formatting breaks. I have checked the version numbers and the core and database are both 5.6.0.2. When I delete
define('DIRNAME_APP_UPDATED', 'concrete5.6.0.2');
in the site.php file, the site reverts back to the main 5.5.2.1 core and the page formatting is correct.

I am using a custom theme that is working properly in another installation running on version 5.6.3.2.

The two issues that are coming up are:

1. The ccm.app.css file is overriding the .container width of 1000px in my theme with a .container width of 940px.

(Note: I read elsewhere that the ccm.app.css in version 5.6.0.2 contains generic selectors that cause conflicts so I changed the .container name in my css and the width issue has been resolved.)

and

2.
<img src="<?php echo $this->getThemePath(); ?>/images/gold_bord.gif" />
no longer displays the image.

Any ideas on how to correct this so I can continue upgrading this site to 5.6.3.2 would be greatly appreciated.