Simple little one in both vb.net and C# When you have a Multiple Selection
Listbox whether it is static or dynamic and you wish to have previous entered data for a view page to be selected it is imperative that you enter the code for each selection as follows:
in vb.net
lb_cause.Items(1).Selected = True
where 1 is the value for the list item in the listbox
and c#
lb_cause.Items[1].Selected = True;
Never, ever use lb_cause.
SelectedValue = 1
Thats all for now.