Dennis, do you have 1.8 installed or are you running from the .dmg? I don't suppose that could make the difference, could it?
Have you gone through your example project and double-checked to make sure the actions themselves have due dates? Or maybe better yet, try creating a brand new test project like this and I'll do the same:
- Test Project - Action Group - Action 1 - Action 2 (due tomorrow) - Action 3 (due tomorrow) - Action 4 (due tomorrow) - Action 5
So mine looks like this in planning mode:
And here it is in context mode (with view bar settings similar to the due perspective):
Does yours look anything like this?