Do you know where is Newfoundland is? Well, I didn´t :$
Anyway, there's a new update for Exchange Server 2003 SP2 in order to fix DST changes for Newfounland.
Update for daylight saving time in 2007 for Newfoundland for Exchange Server 2003 Service Pack 2 (SP2).
Starting in the spring of 2007, daylight saving time (DST) start and end dates for Newfoundland will transition. DST dates will start three weeks earlier (12:00 A.M. on the second Sunday in March) and will end one week later (12:00 A.M. on the first Sunday in November).
There is a Knowledge Base article about this issue (KB931915), but by the time of this post it wasn't available.