Everyone initially appears offline - this is because they're not on your contacts list. Don't worry, just type in the control room (it's not done using the headset) conversation, and everyone will see it. Though some comments didn't appear as soon as they were typed for me, so I missed a couple as they appear in the correct chronological time-slot, but by the time they do, you've moved on from it.
Chris CT had problems - the instant messages were not being delivered so I emailed my senior shifter. After I added him as a contact, everything worked fine. Weird.
Added:
> >
If you see a rotating circle next to your instant messages, they are NOT BEING DELIVERED! Quite often you will need to add your senior shifter as a contact before this starts working; and you may have to get them to add you as well!
First thing you should probably do is read the previous eLog and shift summary.