Menu At Top Of Screen Disappears

[Tom]

AccessXP in Access2000 mode

I have a membership form with several subforms where membership information is
entered. I have a popup form that displays the membership number, name and
address. I have the following code in the double click event of the membership
number field on the popup form:

Me.Visible = False
DoCmd.OpenForm "FrmMembership", , , "[MemberID] = " & Me!MemberID, , acDialog
Me.Visible = True

When I double click on the membership number, the popup form closes, the menu at
the top of the screen disappears and the membership form opens.

What causes the menu at the top of the screen to disappear? Is it because the
popup form although not visible is a popup form?

Thanks!

Tom