Flickering of the z space environment when pressed with z space stylus

[mihirradia]

Hi,

When I run the program UniIowamain1.py it opens up and I use the Z space stylus as a grabber to grab the object and move around in the Z-space environment. The problem that I'm facing is that sometimes when the stylus button is pressed it grabs the object and sometimes the flickering of the Z-space environment takes place. I do not understand the reason for flickering of the the Z-space.
With this I have attached the zip file that contains all the relevant documents to run the File UniIowamain1.py. I would be grateful, if you could help me out.