Okay, I forced some other users to test it too (sadly no XP user), no one could confirm the crash (Nicotin Win 7, Michael_Schwarz Win 7, Hummel Win Vista).
I also tested it here on another PC running Windows XP but I still can't reproduce the crash.

Edit: @Bunsen, I don't see why the code should crash. It just frees some previous allocated memory and removes the dateText object from the current run loop.
I recreated the function here and went step by step through the code via LLDB and there is no illegal access =/
(Btw, Superku said that the crash occurs in the other timer callback and not in the one that fires every second)