Microsoft may hear some backlash for this.
I work for an IT company with multiple clients from various industries. We've been diligent to apply DST patches for All Windows server versions and for all Linux machines. All of the Linux machines, Windows 2003 servers, and XP workstations updated ok. However, over half of the Windows 2000 servers, which all had Microsoft's tzedit.exe utility used to correct the DST settings for the new dates, did not update correctly. We've been double checking at a number of our client sites, all of which had the manual tzedit utility run on Windows 2000 (since MS didn't provide a patch for anything pre-XP or 2003), and we're having to correct a huge number of those Windows 2000 machines manually since the tzedit utility didn't do its job in every instance.
Its not a technician problem; we have multiple techs at a lot of these sites and we double check each other on issues like this, so there is definitely a problem with the MS utility.