Not sure if this is what you are asking for, but this seems a language problem.
Preferences->Advanced->Tweaks->Set the list of words cosidered to be "articles" for sort strings
per_language_title_sort_articles = {
# English
'eng' : (r'A\s+', r'The\s+', r'An\s+'),
# French
'fra' : (r'Le\s+', r'La\s+', r"L'", r'Les\s+', r'Un\s+', r'Une\s+',
r'Des\s+', r'De\s+La\s+', r'De\s+', r"D'"),
}
default_language_for_title_sort = None
title_sort_articles=r'^(A|The|An)\s+'
More languages here:
http://manual.calibre-ebook.com/customize.html