On line 32, there's a piece of PHP code as follows:
print(substr($site_name,1,15))
which only allows the first 16 characters of your site name to be displayed in the header.

If you need this to be longer, just change the 15 to a larger number. In my case, I changed it to 25, which exactly fits the site name I'm using.

I suggest that der should either allow for a longer name or not limit it at all, which would force the administrator to use a site name of a more reasonable length.

Nice theme, though, so I'm glad you brought this to the Drupal universe. Thanks!