I'm not sure if this is what you are talking about, but in my Settings, under lock & wallpaper, my options for Screen time-out are 30 seconds, 1 min, 3 min, 5 min, and never.
i don't recall this being an option until I recently installed the regedit and began editing. I don't think I've done anything to change this in the registry either. If someone else with a Surround could verify these options, then maybe we can figure out where HTC hides this registry entry, and help out.
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