I've encountered a strange issue whereby some all day events show 1 day earlier on the Samsung Global/Ace, but correct on the any Outlook 2003 based PC which looks at the data.
These events aren't anywhere near the new or old DST times, being in the month of July and August - and they were made during the month of May or July.
The Samsung Global is set to the correct timezone, the Outlook 2003 PC is set to the correct timezone.
It doesn't occur with every All Day Event. A commonality that "may" be a factor is that the all day events could have been shifted forward one day at some point in their lifetime. Though we haven't been able to confirm this or replicate the behaviour this at this point.
Exchange, Outlook, Windows, Samsung Global - every device involved in the process have the latest updates.