Need Windows Time Service Expert

I really need some help. I administer a network with ~ 12 nodes all xp pro sp2.
Server is 2003 SBS. The time on the SBS is correct and is the only server on the domain and of course is the DC. About half on my xp pro machines refuse to keep the manually updated time after having to manually change them because of the early DST. They are all set to the SBS as the sntp. If I manually change them after the time service update cycles they return to one hour earlier.
net time output>>>
C:\net time Current time at \\CAOMSFS1 is 3/13/2007 3:31PM

Local time (GMT-05:00) at \\CAOMSFS1 is 3/13/2007 4:31 PM

The command completed successfully.

"CAOMSFS1" is my SBS of course.

I can stop w32time service of course and it will stick.
What I am doing wrong on this? Is there a patch that I need to apply to some of the machines?

 

You shouldn't be having any problem as Microsoft released updates for all XP/2003 variants. Windows 2000 is no longer receiving mainstream support, but as you stated, all of your nodes are Windows XP.