Link-type problem + 2 others.

Greetings from a newbie (groan).

I've just started using MrProject in anger, and have found the following
problems:

1) Setting the predecessor link-type to FS,SS,SF or FF has no effect on
the start and end dates of a task.

2) The lag time seems to have no effect.

3) Highlight critical path doesn't seem to.

I've searched through the list archive, FAQ and user guide and can't
find anything to indicate anyone else having problems, and wondered if
I'm being obtuse or if these are features that are not yet available.

I'm running under RedHat 9 with KDE desktop (but with all Gnome S/W
installed also).

Any help would be appreciated, 'cos I really want to be able to do this
without Windoze.

Thanks, James.