I have a Remote Control Policy setup and I can connect to a worksation and
take control but only when the user is logged in. Otherwise I get a "1802
error: the operation is currently unavailable on the target machine".

I have Zen 6.5 Update 2 and the latest Zen 6.5 agent.

I have the exact same thing setup at a different location and it seems to
work all the time, not just when a user is logged in.