Are you sure that you declared selectedString As
Int when you ran it?
It should have work correctly.
The problem happens when you use Strings instead of numbers. This problem is fixed for the next update (though it is still recommended to correctly declare the numeric variables).
BTW, it is difficult to read posts with code and text together. You can use the {code} {/code} tags to make it clearer (it should be square brackets instead of the round brackets):
dim selectedString as int
selectedString=1
selectedString = selectedString +1