General :: How To Remove A Item (double Var) Of Listbox

I have to do a app in access2003. My problem is when i try remove a item of a listbox not do it right. Example.

values of the listbox:

1
2,5
3

If i remove 1 or 3 not problem but if i try remove value 2,5 my list box show:

1,5
3

why??

my sentences if like this:

listbox1.removeItem(listbox1.ListIndex)

To introduce values i do a query and put them with listbox.addItem(value)

Perhaps any property of the listbox or something i am making wrong.