DST bug in (some versions of) Windows

Last night I have been hit again with Daylight Saving Time bug in Windows. All my PCs are in the GMT-4:00 Santiago TZ. But for some reason ever since Windows 2000 (if I remember correctly), DST switching for my TZ happens a day before than it really should. So I keep DST turned off on all my PCs... except for the newest one running Windows 2003. For some reason I thought that Microsoft has actually fixed this bug (apparently I was in Daylight Dreaming Time when I installed the OS) so I left DST turned on. At 12AM Windows smoothly switched to 1AM thus producing a cascade of updates (through my own doing) on all other PCs and clocks. Only this morning I remembered that the switch is done on Sunday morning, not Saturday morning (I usually check the official time page for Chile but I forgot to do that last night - such is the power of my belief in Windows ;) Well, no harm done this time, it's just annoying (some of the household members woke up an hour earlier but figured out the situation quickly... after all the TV is never wrong! ;)

UPDATE: Some good news - MS fixed this bug in Vista! I just checked on my RC1 and this is what I get:


This is cool. Finally some transparency in the matter!