Turns out the first version of Microsoft's 2007 DST patch has some flaws. If you've downloaded the update before or on March 5, 2007, you'll need to get the new version, unless you want your appointments from March 11 to April 1 to be an hour off.

To recap, the US Congress has passed a law requiring that for 2007, daylight saving time start a week earlier (March 11) and end a week later (November 4). Which means those who never spend time in North America or do business with anyone based won't need to patch their Windows Mobile smartphone or PDA.

New version, but same location. Visit Microsoft's website to learn how to download and install the patch.

Thanks to PDAStreet for the heads-up.