extended value block is not valid

  Explanation:  This warning occurs as the result of a programming
  decision.   The  program read the Extended Lock Value Block, but
  the previous writer  wrote  a  Short  Lock  Value  Block.   This
  warning  message  is  returned  if  the caller has specified the
  XVALBLK flag in the flags argument to  the  service  to  request
  locks.  Note that the lock has been successfully granted despite
  the return of this warning message.

  User Action:  This error message indicates a possible  error  in
  the    locking   protocols.    Contact   your   Oracle   support
  representative for assistance.