[uml-user] hanging uml processes after schutdown

[Andreas S. <an...@sc...>]

i have two processes left, after shutdown of my uml machine:
 5550 pts/8    S+     0:16 /usr/bin/linux (debian) [halt]
 5552 pts/8    T+     0:03 [linux]
when stracing the processes i see that 
the first one is doing a waitpid on the second one.
the second one i cant strace, not even as root.

what can this be? how can i do a clean shutdown?