Try the following code to place the user in the maze and lower the eyeheight so they are not above the height of the walls:
Code:
import viz
viz.setMultiSample(4)
viz.fov(60)
viz.go()
ground = viz.add('ground.osgb')
maze = viz.add('RoomMaze2.dae')
maze.zoffset()
viz.MainView.collision( viz.ON )
viz.MainView.setPosition([-13,0.5,0.5])
viz.MainView.setEuler([90,0,0])
viz.eyeheight(0.5)
Are there textures for the walls and floor or did you change the material some other way? I'm not sure what material changes in blender carry over to the collada file. You might try loading the model in another viewer that supports collada and see if it also happens there.