My preferred way to manage the time on my photos is to leave all of my cameras on GMT and then adjust to the correct time zone on import. Since I'm in the UK, I haven't had any problems doing this since my time zone was GMT. Now that we've had our daylight saving adjustment, it's obviously changing the time zone from GMT to BST now.
Most of the time, this is working fine. But, every now and then, it appears to fail to make the change. Even more strange is that it forgets to make the change half way through an import.
As an example, I shot an ice hockey match last night and, as usual, dedicated a memory card to each period. First and third periods imported fine. The first 50 or so photos from the second period imported fine. The next 250 do report that they are in BST, but have not had the hour added.
Anyone had similar experiences?