Example:
Today is Thursday. If I have a task as a Milestone/Project due next monday with subtasks (next Actions), and one more subs are dated before monday the subs will not be shown in the appropriate sections (date) of the week view, e.g. in the today, tomorrow and so on sections.
I always have to look Info the parent.

So, IMHO it is most likely that a Task (Sub) gots missed...
Hope i described it clearly ;)

Please consider this for improvements...