Must variables be unloaded before the code ends?

For instance do these need to be unloaded, and what is the correct syntax?

Dim i As Integer, pronume(0 To 6) As String, grtot As Integer, starter As Double, finish As Double


I'm asking because there are many pages and the program blocks after maybe 10 pages, also I am asking because I remember that when I used VB this used to be a common problem.
Well, VBA is not the same thing a VB, but I guess you could say that they're first cousins

Large presentations typically don't cause a problem, even with a lot of VBA

I don't think presentations routinely blocked after maybe 10 pages, even in 2007


But as I have said already, without having something look at, it's very hard to tell what might be wrong