zimpff -- I'm not sure what's going on. It might be easiest if you sent your files in to
omniplan@omnigroup.com and one of our support ninjas can take a look.
mercury7 -- How did you get your "work week set to 7 days a week" ? You need to adjust both the effort conversions in the project formatting inspector and the normal work week for the project in the calendar view. If you only changed the effort conversions, but didn't add work time to the calendar on Saturday and Sunday, they won't show up in the Gantt chart.
Choose "Calendar View" from the View menu. Make sure that you're viewing the "Normal Work Week for Project". Then drag the green bubbles left and right, so that they cover Saturday and Sunday too, or drag out new bubbles if you work different hours on the weekend.