Then report it as a bug.  I often get annoyed that sendtoaddress does not allow sending unconfirmed inputs.

On edit:
Is 19VuPF5XHfp435YBMG3f1F3oXZ9BvS2eTe also an address in the same wallet?  i.e. did you send your balance from one address you own to another one you owned?  If so IIRC bitcoind allows spending that unconfirmed input because it knows that it will be eventually confirmed.  Maybe that behavior should be changed?  Still I would ask WTF did you do that if it is the case?