Hi Bert,
I had the same thing happen to me when I tried to install the Squeeze Center add-on. I downloaded the file from the other site as it said in the directions. I then copied that downloaded file over to the volume one folder and ran thru the add-on routine again. This time it reported back that the Squeeze Center software was successfully installed. With firmware 1.03, I got Squeeze Center version 7.6.1. That was a little while ago, so maybe now there's a update I haven't gotten. Be sure you are staying with software update files that are specific to the country you are living in so you do not end up with unexpected results and problems. There seems to be a lot of bad experiences in this forum on that matter.
Take care, Earle