Not sure if this is important or relevant but I'm no longer having issues, I changed a setting in my Avast! program and it now updates on startup and with every subsequent time after (depending on auto update setting), the thing I changed that changed everything was in the branch in the "Update" section, by default I believe the option "My computer is always connected to the Internet" is unticked and through some thorough testing and constant investigation of the Win 7 Resource Monitor. I was able to determine that when this option was unticked, the updater application instup.exe would never run automatically, no matter what. (Even if you have auto updates on :/)
After changing this setting to being ticked though it starts up on startup to check for updates and runs every 3 hours after this (my settings are set to 180 minutes), might wanna try this -midnight and see if it works for you, friend.