Kubuntu LTS, won't turn off monitor

[Rod Lovett]

Hi, despite configuring the monitor to turn off after 2 hours, it just 
freezes whatever Kscreensaver is running at the time, all day or night 
if you leave it. It wakes OK though.
This seems to be the case since applying updates.
And installing Seamonkey 1.04 from the Seamonkey 1.04.tar.gz, as I have 
grown tired of waiting for it to make the ubuntu repos as a package
Now one has to configure a blank screensaver to save the poor screen
Why is this so?
Any suggestions appreciated.
Cheers
Rod