Linh,
I'm not even using an <ID> element in this case - i'm still at the point that i'm just trying to create objects.
What's strange is that it was working before, but i'm at a loss to diagnose why it stopped.
I even set up a Web Services based integration to run the records in 1-by-1 to try and identify errors. As far as i can tell, it's not returning any errors or even warnings through the Web Services based integration.
You might also try removing the "List processing" option and see if you can run in 1 record at a time, which at least might provide some indication as to what's wrong.