Well, I was hoping what you reported was true, but I may as well go for the 4.8 upgrade after another backup of this iGloo!
I
think they finally got all the bugs out by now...
The way I read the DST updater was that there is a stand alone one for Panther. But the one for Tiger requires 10.4.8. Even though 10.4.5 had the needed changes for the US of A, there have been changes in other parts of the world which will only be accessible if you do the new updater. The only problem for a US of A user might be when they receive a message/file from one of the newly affected countries.
Sometimes I can get a different interpretation of a paragraph just by reading it again!
And English is
supposed to be my 'native' language!