Error Handling When Using VB 2010 Express?

I used the following code(with bug):

Code:
For n = 0 To 100
If saveLine(n).Substring(0, 8) = "heading:" Then
cboSelect.Items.Add(saveLine(n).Substring(8))
End If
Next n

The For loop only ran 5 times. It turned out that saveline(5) was shorter then 8 characters, so I changed the code which solved the problem:

Code:
For n = 0 To 100
If saveLine(n).Length > 8 Then

[code]....

VB 2010 neatly exits the for loop when the bug occurs. In this case it was easy for me to pick up the bug, because the combo box was not properly populated. What if it was not obvious that the for loop did not complete? It is quite scary to think that bugs like this are not displayed at run time.