I think xset -s off turns off the screensaver. I saw somewhere that turning off DPMS would stop it, so I typed in the terminal xset -h and there was this bit of info.
Typed in xset -dpms, then entered xset -q & it said DPMS was disabled.
To control Energy Star (DPMS) features:
-dpms Energy Star features off
+dpms Energy Star features on
dpms [standby [suspend [off]]]
(also implicitly enables DPMS features)
a timeout value of zero disables the mode
You might try that.