You are correct that you were able to do that in Vizard R1. In an oversight, that functionality was not carried over to R2 but it will be corrected by release 2.11 (2.10 is the current version) which you can expect in less than two weeks. Thanks for pointing this out to us.
In the meantime, you can try the following since you seem to be only trying to change the height of the user:
Code:
myHeight = 0.0
def mykey(key):
global myHeight
#.....
elif key == '65366': # Page Down
myHeight -= .1
viz.eyeheight(myHeight)
elif key == '65365': # Page Up
myHeight += .1
viz.eyeheight(myHeight)