My initial tests have shown that Robot won't work without an active, visible desktop. For example, while a scheduled task (or executed command from the continuous integration server) may be able to start robot as a command-line process, Robot will actually fail to execute the recorded script.
Logging into the build machine to allow it an "active desktop" is not an acceptable solution.
Am I missing something? Is it possible to run a pre-recorded Rational Robot script on a continuous integration server in a manner that doesn't require the machine to be physically logged into?