Our customer first noticed this when they were testing a power scheme (before LANDesk 9 agent) of setting a monitor to power save after 15 minutes.
In the normal standard arrangement for their environment the screensaver was set to enable in 10 minutes of inactivity, however users could always modify this standard value, and either increase the timeout value or even completely disable it. What was realized by simulating a screensaver timeout value of 20 minutes was that when a monitor goes into power save mode before a screensaver kicks in, the screensaver will not activate at all even after the required amount of time has elapsed. The importance of the activation of the screensaver for out customer was one of security since they are also ticking the box for "on resume, password protect". In the case where a screensaver value is greater than the power save mode, this would leave a device vulnerable to a simple social engineered security breach. Anyone could walk up to a computer with a monitor off, wiggle the mouse and possibly have total access to the device unsecured.
My question for the forum is has anyone experienced this scenario, and what's your take on it if you have? Will you vote up an ER request to LANDesk to try and help resolve this deficit in the OS should it exist in newer OS versions? I have yet to test this issue on anything but XP. It might be corrected in 7? Anyone want to check it?
What I have determined so far on developing a solution to this is that it will likely require a sort of service that runs at least while a user is logged in, and watches for broadcast messages relating to power state changes for a monitor. It appears to be impossible to just read a value anywhere to tell what a monitor's state is, so it requires something that actively listens for the signals that indicate that its state is changing. Once a state change is detected, the service would then simply issue a lock command to the OS obviosuly when the monitor is put to sleep only. It wouldn't be necessary for it to try and activate the screen saver since the monitor is off and shouldn't need it. Its also very easy to lock a machine with a simple dll call.
We tested a Windows 7 device today, and found that the power save mode and screen lock functions work properly, so it seems this is an XP flaw only.