automatic update flaw?

In the control panel I have Automatic Updates set to everyday at 3:00 but
for the second time in the last year I went to windows update site to see if
there were any new optional components and I found it said my update
software needs updating. After I do that I see there are like 19
High-priority updates available.

Shouldn't these have been downloaded automatically? Isn't the auto update
feature a security risk because it gives people a false sense of security?
I totally thought my system was being updated automatically when its wasn't?

Bob