Memory card failure?

I just ecently found out that you could eneter your own name into the memorycard. I have just one problem; I can't enter "o"; the cursor just skips it when I try to enter it. Is this a common error?

I think that's the letter that also skips on one of mine. But I kept moving the cursor and it went to "p" or some other letter twice and one of those trips gave me the "o." So, try that & see if it does anything.