Background Manager will not Activate

I am using the Annotum Theme at mikeperazzetti.com, and I have been told by my hosting provider that I have the latest version of PHP but I keep receiving this error. The hosting provider suggested I go into the .htaccess file to add the string

# Use PHP 5.3
AddType application/x-httpd-php53 .php

to make this work but that did not help (unless I added it in/to the wrong line.

Error: Unsupported version

The plugin “Background Manager” requires PHP version 5.3.0 or better.

Because of this error, the plugin was automatically deactivated to prevent it from causing further problems with your WordPress site.

Error source: /home/mikepera/public_html/wp-content/plugins/background-manager/background-manager.php

I would really like to make this plugin work for me because I feel it will be useful, but my efforts have come to naught at this point.

Hope you can help,

Mike Perazzetti