clearing playlist in media control

[xboxhardcore]

First off what my program does:
It is a spelling program, it takes strings breaks them up charactor by charator then plays a wav file that says the letter. Eg the if the string is "hello" it would play a wav
"h.wav" followed by
"e.wav" followed by
"l.wav" followed by
"l.wav" followed by
"o.wav" followed by

Ok on the first run everything is sweet, it works without worry or hassel, but on the second click it just says the last letter, in this case "o.wav", even more odd, if I chnage the string (without closing and re-opening visual basic) it will still just play "o.wav"

I need a way to reset the media player so I can replay, or set a new string of wavs for it to play

[xboxhardcore]

Update: It seems that the last letter is repeated for the length of the new string, making me even more lost, any ideas?