Using New Collection Method For Make Uniq Item

I like using New Collection method for make Uniq items as below
(using excel and his vbe only)

'Option Explicit
Option Base 1
Sub UniqDataMaker()
Columns("D:M").ClearContents
Dim i As Double, j As Double
Dim rng As Range
Set rng = Range("AllData")
Dim STRrng
STRrng = rng.Value
Dim adds As New Collection
On Error Resume Next
For i = 1 To UBound(STRrng)
adds.Add "'" & CStr(STRrng(i, 1)), "'" & CStr(STRrng(i, 1))
Next

On my think...
if occurs error number 457 then
resume next and add only new items only.

Just yesterday
When occurs error number 457 then the coding is always stop with msg error 457
I checked and re-install office, and re-boot.
but stoped that line with error 457

with this file or coding
other PC never occurs error

I use Excel version 2000,xp,2003 but never finish job. -_-;;

adds.Add "'" & CStr(STRrng(i, 1)), "'" & CStr(STRrng(i, 1))
-> error.
adds.Add CStr(STRrng(i, 1)), CStr(STRrng(i, 1))
-> error.

I did my best, but I give up;;

some one know why stop error 457?