Im getting the same issue ussing an artisteer created theme however There is no code in functions.
Under comments is this
// Produces an avatar image with the hCard-compliant photo class
function commenter_link() {
$commenter = get_comment_author_link();
if ( ereg( '<a[^>]* class=[^>]+>', $commenter ) ) {
$commenter = ereg_replace( '(<a[^>]* class=[\'"]?)', '\\1url ' , $commenter );
} else {
$commenter = ereg_replace( '(<a )/', '\\1class="url "' , $commenter );
}
$avatar_email = get_comment_author_email();
$avatar = str_replace( "class='avatar", "class='photo avatar", get_avatar( $avatar_email, 80 ) );
echo $avatar . ' <span class="fn n">' . $commenter . '</span>';
The problem is theme related.