The software updates come via the DISH, not your phone line (all the phone line is for is to report your PPV's and so you can use your caller-ID).
If you want to be sure to get the update, you can either turn your receiver OFF at night so it can be downloaded while you aren't watching, or (as I do), you can go into the menu and turn ON automatic updates. It'll ask you for a time you want the updates... set it for a time you aren't usually watching TV (for example, mine is set for 4:00am).
If you have the updates on, it'll automatically download the new program guide and check for updates - and if you have the 522, it'll do disc-checking for errors.
Hope that helps... just turn it off at night, or turn on updates.