does yours randomly.. "log you off" if you don't keep it active?

for instance if I goto work or goto bed, and come back to it hours later.. the next time I log into it through remote desktop, it's been logged off and all the programs are closed. I know it's not just loading another session because I've opened "Terminal Services Manager" and there's only my current session running.

this sucks, because my torrents don't get seeded the entire time I'm sleeping/work/or gone somewhere.

any idea how to fix this?