Motorola ROKR Z6m

i have a moto rokr z6m .. i have a ringtone i made that seems to be corrupt. the problem is .. is that it doesnt show up in my sounds now.. so i could move it from my fone back to my memory card to delete it. it still shows as a ringtone under my ringtones list.. tho it will not play and i cant figure out how to delete it. please someone help! 😕