Not entirely the same situation, but I had a lot of trouble transferring points from my UR account to my wife's. Using her card number and lastname, it gave me the "Unexpected Error". Called and representatives couldn't get it to work though confirmed it should, and were "unable" to do it manually.

We have a checking acct with Chase and I noticed my wife's name included a middle initial on it. I tried once more to transfer points to her account using the middle initial, space, lastname, (entered as "A LASTNAME") and it went through. It is certainly not printed on her card like that but she does have multiple middle names that tends to confuse lots of things.