[AccessD] DoCmd.OpenFrom acHidden is not hidden

Hi all

>From a form I try to open another form hidden by clicking a button:

  DoCmd.OpenForm "frmSomeForm", acNormal , , , , acHidden

Then the hidden form is supposed to do some calculations and, when finished,
unhide itself by means of a not visible textbox bound to a function:

  =SetVisible()

which contains:

Private Function SetVisible() As Boolean 
    Me.Visible = True 
    SetVisible = True 
End Function

The sequence works except for one thing - the form isn't opened hidden
because its frame is shown at once.
Thus, the sequence is:

1. Frame of hidden form is shown on top of the calling form. The form itself
is transparent so the calling form is still visible inside the frame.
2. The "hidden" form performs the calculations.
3. The "hidden" form paints its inside invisibly.
4. SetVisible is called.
5. The completed form is visible.

I've also tried opening the hidden form with:

  Set frm = New Form_frmSomeForm
  frm. Visible = False

No difference. Also having this in the OnOpen event of the form:

  Me.Visible = False

All to no avail.

Any ideas for opening a form completely hidden?

/gustav