Multiple Open Processes Conflict (Linux)

[Bojsza]

I have to buttons that each start and stop different processes, with 
the output of each process being placed in separate fields.

I also have a field that I can see the processes that Revolution has 
opened and the order in which they were opened.

The problem I have discovered is that I must close the processes in 
reverse order for them to actually stop.

Example if I start process A and then start process B.
Both fields A and B are updated with the process output and the 
processID list shows
process A
process B

When I select the stop button for process A , the output of the process 
A stops but the processID list still shows
process A
process B

(I have confirmed that both processes are running by ps -aux command in 
a shell window.

If I then stop process B then the output of process B stops and both 
processes stop.

But if I do it in the reverse order...stop process B first then the 
output for process B stops and the list shows
process A

And then I can stop process A and its output stops and the list is 
cleared.
(again I confirmed this ps -aux in a shell window)

Is this a bug or do I need to close a process by some other method?

Currently I close the process exactly how it was open

close process "trace -r test"

If using multiple processes do I need to use the kill command (doesn't 
seem graceful?)