codefilter.css does not support CSS aggregation

Sorry, anyone can explain me why is not possible compress codefilter.css file into other CSS?
into code you use:

/**
 * Implementation of hook_init()
 *
 * Adds the codefilter stylesheet to the page
 */
function codefilter_init() {
  drupal_add_css(drupal_get_path('module', 'codefilter') .'/codefilter.css', 'module', 'all', FALSE);
}

i change it into:

/**
 * Implementation of hook_init()
 *
 * Adds the codefilter stylesheet to the page
 */
function codefilter_init() {
  drupal_add_css(drupal_get_path('module', 'codefilter') .'/codefilter.css', 'module', 'all', TRUE);
}

and file is compress, this can cause some problem?