Auto-update Config does not save?

I have configured my XP to receive critical updates automatically.
Upon checking I noticed that the latest batches were not saved as expected.
I rechecked my config and realised that the auto-update is set for 3AM. As my
pc is off at that time, nothing happens but it appears I cannot change the
default time to a work time. While it shows 9 AM initially, the next time I
go back in to verify, the time has reverted to 3 AM on the initial screen for
"turn on automatic updates". Using more options, the next screen does show
9AM but does not seem to actually retrieve the updates. My preference here is
to download them but let me choose the installation.

Any advice?