Here's my environment: Lenovo W520, Win 7 Pro 64-bit (SP1) 20Gb memory connected to external keyboard, trackball and monitor through a KVM switch (various other machines/monitors on the KVM).
Here's the issue: all the power settings and screen saver values are set to never sleep or hibernate with maximum cooling, performance, etc. Yet when I switch to another machine, sometimes, but not always, after about two minutes, the W520 goes to sleep. There have been times when I start to see the screen dim and tap on the laptop's keyboard to try and stop the process, and I get no response.
While the most annoying occurrence happens when I am using another machine, I intermittently see the same behavior (when I have the W520 selected), but leave the keyboard and trackball idle.
Any help would be greatly appreciated.