Need help with firmware update

I have a Samsung Galaxy S which was purchased online in New Zealand. It has been unlocked and I assume it was imported from somewhere else by the online store I got it off.

I have it connected to Vodafone New Zealand.

I have the latest version of Samsung Kies (v2.0.0.11032_12) installed and when I connect the phone to my PC and go to the firmware information section it says:

This version of the device cannot be updated.
Current firmware version: PDA:JM2 / PHONE:JM1 / CSC:JM2 (TMH)

When going into 'About Phone' on the phone the following information is displayed:

Model number: GT-I9000
Firmware Version: 2.1-update1
Baseband Version: I9000XXJM1
Kernel Version: 2.6.29 root@SE-S603 #2
Build Number: ECLAIR.XWJM2

From the information above can anyone determine who the provider/country it was originally from and why it would not be allowing the firmware to be upgraded?

Does anyone have any sugestions on how I can upgrade this to the latest firmware?

Looking on samfirmware.com, it looks like a European 2.1 version. I personally never bother with Kies. I did try (again) with my new SGS but it screwed it up (again). The best way to upgrade is to download the stock firmware for your region. If this is America/Australia, the latest version is I9000BVJJPD (2.1).

use ODIN to flash the new version, you wil then have an unbranded phone with no carrier bloatware. I personally then choose a custom ROM (currently running speedmod 13e), this makes the phone VERY fast and stable.