iAVS updates can be downloaded as they are created and released.
The program updates are released but to cut the load on the servers the auto update check happens every 7 days and not checking every time you connect to the Internet as with the iAVS checks.
You can however, as you have found perform a manual update. Monitoring the new forum, 'ALWIL Software Announcements' will give forum regulars a heads up on any announcements, like updates, etc. So forum users have another benefit.
