Currently TbBreadcrumbs is drawn correctly, only if only last element is a string:
$this->breadcrumbs = array('Group'=>'#', 'Title');
All preceding it has to be a links or else, will be drawn incorrectly. If any of preceeding elements is another string (not a link):
$this->breadcrumbs = array('Group', 'Title');
it is drawn glued to next item, without required space and separator in the middle.