I have this plant pot that I've been trying to find a way to fix this issue. When it prints, it prints as 2 walls going up. I'm trying to get the model to print with 1 wall going up, like a vase mode. Even with vase mode enabled in S3D it still prints 2 walls. If you run the file through you will see what I mean. Basically trying to make it print 1 wall the entire way up to save time and materials. You can get the planter here..

http://www.thingiverse.com/thing:698864