dynamic array redim preserve: run-time error 9, Subscript out of range.

Hi!

I found quite a few posts about this problem, but none of the answers was any use to me...

I need to redimension a 2 dimensional array in a Sub. I deleted all the code that is not of interest:

Option Explicit 
Dim Gear() As String                   'I also tried "Private" and without the "As String", or givin a specific dimension right here.

Sub Workbook_Open()
Call setup_arrays

If Gear(i, 1) = "son-and so" Then 
   [blablabla]
End If 
End Sub




Sub setup_arrays()

ReDim Gear(8, 2) As String        ' I also tried "Redim Preserve"
    Gear(1, 1) = "a"
    Gear(2, 1) = "b"
    [...]
    Gear(8, 1) = "c"

Do While temp = "6"                  ' this is of course true, when testing...
    MsgBox "the code works fine until here!!!"
    ReDim Preserve Gear(UBound(Gear) + 1, 2) As String                  ' this code causes the error! All I want is to increase the first dimension of the array by 1, while the second dimension remains untouched.
    Gear(UBound(Gear), 1) = "d"
Loop

[...]

End Sub

Can somebody tell my why I receive the Run-time error '9': Subscript out of range"?.... or even better, tell me how to avoid it?

Thanks in advance!

Broesel