I am trying to improve my command line skills and I have encountered a problem where I cannot kill a process. I type kill 2200 where 2200 is my PID and the process is not killed. After few minutes wait is still in the top and ps aux.
I have even tried typing it with sudo - no results.

Any ideas why it would be like that ?

EDIT

I have found a weird dependency, where fg updates the processes list:

x@xxx:/etc/grub.d$ ps

  PID TTY          TIME CMD

 1723 pts/0    00:00:00 bash

 2200 pts/0    00:00:00 top

 2202 pts/0    00:00:00 top

 2258 pts/0    00:00:00 ps

x@xxx:/etc/grub.d$ fg

top



x@xxx:/etc/grub.d$ ps

  PID TTY          TIME CMD

 1723 pts/0    00:00:00 bash

 2200 pts/0    00:00:00 top

 2620 pts/0    00:00:00 ps

x@xxx:/etc/grub.d$ fg

top



x@xxx:/etc/grub.d$ ps

  PID TTY          TIME CMD

 1723 pts/0    00:00:00 bash

 2621 pts/0    00:00:00 ps