Problem scheduling backward from fixed end
 

I can't figure this out. If I schedule my project forward from a fixed start 12/10/12, it ends 1/25/13. However, I really want to launch on 1/28/13 and push things back a bit. I figure that scheduling backward from a fixed end (1/28/13) is what I should do. However, when I change the project to this setting, the project creates a violation and the project ends on 2/11/13. For some reason it pushes back the project start date to 1/7/13. I don't have any constraints and it shouldn't be a resourcing issue.

Anyone have thoughts on what is happening?

Your best bet with problems with OmniPlan of this sort where words can't faithfully describe what is going on in sufficient detail is to use Help->Send Feedback to send an anonymized version of your document (all task names are replaced with Task 1, Task 2, etc.) to the Omni support group, along with a description of what problem you are seeing. They can get a much better take on whether it is user error or programmer error.