Sorry bud, the smaller the cluster size the faster the access times and speed of the flash media. Here is a whole thread from Pocket PC mag which will help you get the most performace out of you flash media. They explain everything and then run cards through tests to get the best results. The faster access times will increase the cards ability to send the Castlevania intro to the DS ram thus making it run smoother.
http://www.pocketpcmag.com/FORUM/topic.asp?TOPIC_ID=17921
Enjoy,
FifthE1ement
http://www.pocketpcmag.com/FORUM/topic.asp?TOPIC_ID=17921
Enjoy,
FifthE1ement