GUI automation will not work properly in most cases when the screensaver is active (because then no GUI operations may take place, which means that the respective GUI objects may not be found, or they may not have proper screen coordinates).
Although disabling the screensaver has to be considered a must-do for GUI automation, sometimes disabling the screensaver is not an option.
The Java-based tool MouseWiggler.class ( MouseWiggler.java ) may be able to avoid activation of the screensaver by faking mouse cursor movement from the user.
This tool works independently of Squish and must be started on the desired computer. It will run until into stopped (Control+C) or killed.
Example execution:
cd "path/to/MouseWiggler"
java MouseWiggler 30