I think I got it figured out.
The only 600 Receiver that I get the new channels on is the new one I bought last spring (2013-06.) & set up AFTER the major Satellite upgrade.
So I should be ok with the other ones not upgraded. (I think)
Channel 988 on the other receivers asks me to contact Shaw regarding my account.
I take it that means "upgrading" to the new channels.
BTW if I was not ever going back to the USA with my receivers I would upgrade all receivers as there are a lot of good HD NEW Channels now available.
Here is some info on Shaw Direct's site on their Q/A's
Do I need to upgrade all my receivers?;
No. In order to view the channels on the new satellite, you may require an outdoor hardware upgrade and a 600-series receiver inside your home. If you have multiple receivers in your home, you only need to upgrade the ones you would like to view the new channels on. Your old receivers will continue to work and continue to receive the same channels they get today.