It appears that there is problem with MS DST patch.  One of our reader, Ray, notify us about MS DST patch (931836) problem.
Regarding this patch problem more information can find from here.  If you have simillar problem, please let us know.
At this moment, we didn't hear from MS yet. If we got more information, will update it.

Update :  There is another fix patch available for Windows-based applications that use the TZ environment variable may not work as expected because of changes to DST. More information available following link (http://support.microsoft.com/kb/932590/en-us)

Update : Our reader, Alan, notify us for MS Mobile Update for DST patch, the patch is available here.