If I try to enter '0.5' into the "Wait:" field in screen saver settings, I get this error when I press the '.':
I want to activate the screensaver in half a minute.
The only solution I came up with was to write a program to monitor user input, and activate the screen saver after 30 seconds of no activity. If worse comes to worse, I can do that, however I prefer to simply change it in the windows system settings.