Loop causing duplicate in list of string

[PSYCHONAUT]

I am pulling my hair out on this one, any help would be greatly appreciated as need to finish this project soon. Basically what happens is each time it loops through it adds a number to the end of the string, and by the end I should end up with an array full of string in a format like "111 222 333 444 555 666" but I end up getting strings like this "111 111 222 222 333 333". The weird thing is, if I add a message box in every loop it works fine, but obviously I don't want a message box pooping up every time it loops through. What is causing this and how might I fix it? Many thanks.

The code is:

        For x As Integer = 0 To (NumCards.Value - 1)
            NumRep = 0
            CardList.Add(RanFun(CardNums) & " ")
            For s As Integer = 1 To 5
                y = RanFun(CardNums)

                Do Until y <> NumRep
                    y = RanFun(CardNums)
                Loop

                Dim WinCount As Integer = 0
                Dim CaAr As Array = CardList(x).Split(" ")
                For Each num As String In CaAr
                    If num IsNot "" And num IsNot " " Then
                        If num = y Then
                            WinCount += 1
                        End If
                    End If
                Next
                If WinCount = 2 Then
                    For Each gy As Integer In WinNums
                        If y = gy Then
                            If NumRep = 0 Then
                                For wn As Integer = 0 To 8
                                    If WinNums(wn) = y Then
                                        If WinCheck(wn) > 0 Then
                                            NumRep = y
                                            Exit For
                                        Else
                                            Dim yy As Integer = y
                                            Do Until y <> yy AndAlso y <> NumRep AndAlso CharCount(CardList(x), y) < 2
                                                y = RanFun(CardNums)
                                            Loop
                                            Exit For
                                        End If
                                    End If
                                Next
                            Else
                                Dim yy As Integer = y
                                Do Until y <> yy And y <> NumRep
                                    y = RanFun(CardNums)
                                Loop
                            End If
                        Else
                            Dim yy As Integer = y
                            Do Until y <> yy And y <> NumRep
                                y = RanFun(CardNums)
                            Loop
                        End If
                    Next
                Else
                    'Do nothing
                End If
                MessageBox.Show("Blah") 'this message box causes correct functioning
                CardList(x) = AddString(y, x, CardList)
            Next
            ProgressBar.Value = (x / NumCards.Value) * 100
        Next

Edit: I even rewrote this whole piece of code hoping that would fix it but still the only thing that would work was a message box.