Compiz looked like it worked. But it didn't work.

So the solution to this is the following.

First we check available modes.

$ xrandr

1440x900       59.9+*   75.0

1280x1024      75.0     60.0



Then we pick the mode, including resolution and refresh rate.

$ xrandr -s 1440x900 -r 75



Or just the refresh rate

$ xrandr -r 75



Let's see if it worked

$ xrandr

1440x900       59.9+    75.0*

1280x1024      75.0     60.0

Alright. Then all you have to do is add the command to Startup Applications and be done.