throttle_process() used with bogus pid

[petterreinholdtsen]

When I try to run appfab, I get repeated messages like this:

Traceback (most recent call last):
File "appfap.py", line 40, in on_active_window_changed
throttle_process(pid)
File "appfap.py", line 10, in throttle_process
f.write(str(pid))
IOError: [Errno 3] No such process

I tracked it down, and the cause is a bogus pid being used, and it originates from this call in the code:

windows_pids = [w.get_pid() for w in screen.get_windows()]

The array contain pids followed by 149, 0 and 14696, none of which represent pids in the system. Did Wnck change behaviour?