Cannot select ‘Daily Task List’ when viewing other users calendar

We migrated from Office XP to Office 2007. Now when we open another users
calendar, we cannot view their daily task list; it is greyed out under the
View menu. If we display the To-Do bar, it shows my information, not the
person’s whose calendar I’m viewing.

The other user’s calendar also used to open up in a separate window, but now
it is all displayed in a single window. Is there a way to change this?