A: 

The local IT guys managed to identify the answer:

The client PC that was showing "wrong" information (timestamps at 11pm) was missing hotfix KB981793 - a cumulative patch for time zone rules.

Not what I expected at all - but installing that hotfix has fixed the problem on every machine we've tested.

Bevan  2010-08-10 02:47:04
Excellent. Glad to hear you found the solution.
 2010-08-10 03:14:53

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