Comment 5 for bug 874619

I have spend a lot of time trying different setups to test this. The conclusion seems to be:

1) The problem is apparent on both ATI and Nvidia hardware.

2) It only occurs on multiscreen setups

3) It only and always occurs when the Unity plugin to Compiz is active.

Simple reproduction can be done by:

Standard unity desktop session across multiple screens.

Run the attached python program in a fullscreen terminal on one screen.

Try typing in another terminal on another screen.

Python program to spout lines:
----
import time
import sys

try:
    lps=float(sys.argv[1])
except IndexError:
    lps=0

a=0
while True:
    a+=1
    print "Dette er lang linie nummer %d som skal vise om vi kan lave hurtig scroll" % a
    if lps > 0:
        time.sleep(1.0/lps)
----