Let's clarify some more things. You refer to a "jadmin service". Do you mean
the JRun Admin service? Are you running CF in multi-instance (or what's
formally called MultiServer) mode? If so, are you then referring to the
"Macromedia JRun Admin Server"?
Also, you say that this "killed it", but that doesn't seem quite right. Do
you mean it kept it from starting? It's an important difference.
Assuming that's what you mean, I'd ask do you really need it running at all?
It's not really needed from CF7 on, as that has the Instance Manager feature
built into the CF Admin for creating, starting, and controlling CF
instances. The JRun admin is really a holdover from the deployment of the CF
multiserver mode on a "full" JRun instance. If you never really use that
JRun admin, you don't need it for CF, in my experience at least. If you
didn't start it, does everything then work?
It sounds like there's still more to get to the bottom of, and certainly
there's no reason FD should be left causing a conflict (or potential one),
so let us know your thoughts on the above.