Interesting to see this thread. I complained about it on the Mac TV forum a few months ago (Mac controlling remote Windows machine). Pretty aggravating, and ongoing. I get the impression that "Lock on Session End" does indeed turn on semi-randomly, but it also appears to default that way when the remote computer is rebooted. It's not a huge deal, as it just means that the remote computer is left in a logged-off state and someone needs to log back in, but it means that the remote user finds it that way. For me, the remote computer is in a secure location, so there is simply no reason to log the user off. I guess this is mainly surprising given that TV is in other respects a quality product. Now, if it's really true that the system doesn't always default to "Lock on Session End" when you tell it to, that's a major issue for people concerned with security.