print theme() per documentation not working

I made good progress with jplayer today on a D7 website. I installed, created a content type and was able to generate an active player in the content type. All good stuff.

I then tried to use the "Theming" example on the documentation page here: https://drupal.org/node/1095840 . I had to change the following line of code to work with my multiple language D7 website:

  '#item' => $node->{$field_name}[0],

to

// you may need to add a language code a multiple language website
  '#item' => $node->{$field_name}['und'][0],

You may wish to add this as a comment on the documentation page.

I executed the resulting code segment in a "Page" content type with the PHP filter enabled. The result was no errors generated to the screen or logs/error_log. Unfortunately these was also no player generated either. I looked at the source of the resulting page and I believe no code was generated as a result of the following:

print theme('jplayer_formatter_single', $jplayer_data);

I then performed a GREP looking for the string "formatter_single" and found none. Could it be that something has changed and the documentation no longer matches?