.Net3.5 Exception: DataTable internal index is corrupted: '5'. on ...

异常代码：
  private void LoadUserLockDocument()
        {
            if (this.InvokeRequired)
            {
                BeginInvoke(new MethodInvoker(delegate() { this.LoadUserLockDocument(); }));
            }
            else
            {                dtUserLockDocument.Rows.Clear();                List<UserLockDocument> userLockDocument = sysTokenSingleton.UserLockDocument;                foreach (UserLockDocument document in userLockDocument)
                {
                     
                    dtUserLockDocument.Rows.Add(document.Database, document.UserIp, document.DocumentType,
                        document.LockOutTime, document.PK1, document.PK2, document.PK3, document.PK4, document.PK5,
                        document.PK6, document.PK7); // 这里抛出异常                }
                dgvLockDocumentList.DataSource = dtUserLockDocument.DefaultView;                dgvLockDocumentList.Invalidate();
            }
        }