What version of VP is being used? Try setting your preview resolution to 864x1080, then edit so things look right.
If that doesn't help...
Click the SEQUENCES tab above the bin (top-left of the window).
Right-click on the Sequence 1 folder and click on EFFECTS.
Is there an effect shown?
If so, delete it with the red X and try your export again.
If these measures fail please share your project. It's not difficult. Someone will check it out...
Here's how... http://nch.invisionzone.com/topic/23659-tips-for-getting-help-on-this-forum/
If it contains sensitive material you can link it in a personal message (PM) to me, via the envelope above. Be sure to FILE|SAVE PORTABLE PROJECT AS, not simply SAVE PROJECT, and don't forget to share it.