Pb with the calendar display of CCK dates set with "to-date" option, when the "from" and "to" days are different

I'm still trying to migrate my custom calendar from D5 to D6...
My calendar argument is a CCK-date field with an optional "to-date" part. Currently, I've set the view argument to the "from part" of the field and have done the same for the date field output (see Calendar6-3.png). But the output on the different displays is not good, or let's say not the same as the one on D5 (see Calendar5-1.png for D5, and Calendar6-1.png and Calendar6-2.png for D6). On D6 the from and to times are repeated on every days.
Do I have to add something to the "arguments" or "fields" settings of my view, or is it a bug ?

Hope someone could help.
Thanks !