This is an interesting one!
I have a Ubuntu headless server with a process of flexget which seems to have stuck.
paully 2155 0.0 0.7 232012 121148 ? D 02:00 0:01 /usr/bin/python /usr/local/bin/flexget --cron execute
It is in a D state which means it cannot be killed because it is an 'uninterruptable process is a process which is stuck in a kernel function that cannot be interrupted or stopped mnaually'.
This stray process does not seem to affect the normal hourly cron job but I wondered (a) if I stopped the Cron daemon it would stop itself or (b) if anyone else has experienced this?