Outlook 2007/2010: sendUsingAccount doesn't work

We want to set the account under which the mailitem is to be sent.

modify hMail, @SendUsingAccount, hAccount

But the command doesnt't work, the default account is used.


Example:
We have several accounts in Outlook and we want to use another account than the default -> notthedefault@xyz.com

This VB-Example works:
Private Sub Command1_Click()
    Dim oAccount As Outlook.account 'display all accounts
    For Each oAccount In Application.Session.Accounts
        MsgBox (oAccount.SmtpAddress)
    Next
    For Each oAccount In Application.Session.Accounts
        'send mail with another account, not with the default
        If oAccount.SmtpAddress = "notthedefault@xyz.com" Then
            Dim oMail As Outlook.MailItem
            Set oMail = Application.CreateItem(olMailItem)
             oMail.Subject = "VB: SendUsingAccount"
            oMail.Recipients.Add ("reciptient@zzz.com")
            oMail.Recipients.ResolveAll
            oMail.SendUsingAccount = oAccount
            oMail.Send
        End If
    Next
End Sub


But the Acu-Example doesn't work, the command SendUsingAccount is inefficient:
      *-----------------------------------------------------------------
       main section.
      *-----------------------------------------------------------------
       m-anfang.
           initialize hAppOutlooks.
           move zero to wh-ol-ind.
      *
           create application of outlook handle in hAppOutlook
      *
           modify hAppOutlook, @getnamespace("MAPI")
               giving hNameSpace
           inquire hNameSpace, @Accounts
               in hAccounts
           inquire hAccounts, @Count
               in wh-olkonten-anz
      *
           if wh-olkonten-anz > 1
      *    ---- display all accounts -> OK -----------------------------    
               perform varying wh-ol-ind from 1 by 1
                        until wh-ol-ind > wh-olkonten-anz
                   modify hAccounts, @item(wh-ol-ind)
                       giving hAccount
                   inquire hAccount, @SmtpAddress
                       in wh-olkonto-email
                   display message box wh-olkonto-email
                   destroy hAccount
               end-perform
      *    ---- use a not default account -> problem -------------------    
               perform varying wh-ol-ind from 1 by 1
                        until wh-ol-ind > wh-olkonten-anz
                   modify hAccounts, @item(wh-ol-ind)
                       giving hAccount
                   inquire hAccount, @SmtpAddress
                       in wh-olkonto-email
                   if wh-olkonto-email = "notthedefault@xyz.com"
                       display message box "Found:", wh-olkonto-email
                       modify hAppOutlook, @createitem(0)
                           giving hMail
                       modify hMail, @to, "reciptient@zzz.com"
                       modify hMail, @Subject, "Acu: SendUsingAccount"
      *    -----------------------this command doesn't work ------------
                       modify hMail, @SendUsingAccount, hAccount
      *    -------------------------------------------------------------
                       modify hMail, @send()
                       destroy hMail
                   end-if
                   destroy hAccount
               end-perform
           end-if.
           destroy hAccounts.
           destroy hNameSpace.
           destroy hAppOutlook.
       m-ausis.
           goback.

Who can help me?