I support a desktop application containing datetimepicker components.
A child form loads within an MDIcontainer, updating components from data retrieved from a SQL table, allowing users to make modifications.

A text component hides the current form and displays another form.
When the user returns from the other form, one of the datetimepicker component is unchecked and the date is set to the current date. Tracing through this application, I do not hit any code that resets this component.
Other datetimepickers located in my current form are not affected.

I'm providing the routine used to display another form, and the routine used to return to the current form.

Private Sub txtPubNo_DoubleClick(ByVal sender As Object, ByVal e As System.EventArgs) Handles txtPubNo.DoubleClick
Me.Hide()
SetCalledFromAForm = True
mdiPads.ActivateMDIChildForm(frmPublicationTitleView)
End Sub

Private Sub cmdPubNoViewCancel_Click(ByVal eventSender As System.Object, ByVal eventArgs As System.EventArgs) Handles cmdPubNoViewCancel.Click
frmPADSEntry.Show()
frmPADSEntry.StartPosition = FormStartPosition.CenterParent
frmPADSEntry.Location = New Point(130, 10)
Me.Close()
End Sub

any ideas on this..thanx