A great cheese is still great, even if it has some holes.

Imagine James Cameron's Titanic was released exactly as it is, but the ship hit the iceberg in 5 feet of water, 50 yards from the coast. It would still be award-winning in every way it was, but it would have a couple of plot clangers.
Dark Signal was the same for me. It is a cracking film, beautifully shot, great sound, lovely airbourne tracking shots, genuine surprises. The confusion over when and where some things occured was entirely forgivable, as I am sure some of the scenes that tied the story together neccessarily ended up on the cutting room floor for whatever reason. The film is far better than it's budget. My only real critism involves the use, or rather lack of use, of certain tools at certain points, primarily the main murder weapon being the ideal tool during the radio station cupboard scene, but the primary victim completely ignores it to do something stupid. That is unforgivable, but maybe the film maker did that deliberately, to show how dumb the victims are in these films?
All in all, I loved the film, and cannot wait to watch the next offering from this director.