This is a common issue with the Robo 3D R1. Have a look at this post on our forums, which goes into more detail about it:
http://forums.matterhackers.com/topic/9/what-to-do-if-your-robo-keeps-trying-to-print-up-in-the-air
If you are still having trouble, please contact Robo 3D directly.
http://robo3d.com/contact-us/