Progress Lines on a status date

[David Hans]

Can anyone explain to me why a progress line displayed against a status date
shows progress behind actual progress for:

* summary tasks with general tasks within it; (Progress Shown but only as
far as status date)
* summary tasks with only milestones within it (No Progress Shown even when
Milestones are 100% complete)
* tasks with more progress than the status date e.g. progress is greater by
% complete than status date, (Progress only shown as far as status date)

many thanks,

David.