Description:
------------
If I edit a mp3 file and write only the id3v2 tags in this
(Winamp 5.23) i can not read the tags with MP3_Id

Test script:
---------------
$mp3 = new MP3_ID(true);
$mp3->read('name.mp3');

if ($mp3->getTag('id3v2')) {
	echo "2\n";
} elseif ($mp3->getTag('id3v11')) {
	echo "1.1\n";
} elseif ($mp3->getTag('id3v1')) {
	echo "1\n";
} else {
	echo "unknown\n";
}

if ($mp3->getTag('artists')) {
	echo 'Artist:'.$mp3->getTag('artists')."\n";
}

Expected result:
----------------
2
Artist:name

Actual result:
--------------
unknown
Artist:0