I have the same exact issue. By research on the net I found out that the reason for this is when the firmware has been changed to anything else from stock. In my case, I had updated firmware to ICS (leaked version) from gingerbread using ODIN. In your case the firmware has been changed by samsung service. Anyone knows how to get around this problem and get official ICS, pls reply.
I have a Samsung Galaxy S2,it seems my phone is not allowed to update via Kies.Its shows a message "Your device does not support software upgrading via Kies" when I connect my phone. Has anyone else faced a similar situation
Thanks