Thanks for replying. Because lp:alltray didn't succeed on 'make' I
compiled vala from "bzr branch lp:~vcs-imports/vala/new-trunk". After
that lp:alltray compiled (though with some warnings while the lot of
text was printed, but it completed successfully). I have the same
strange behavior though. 

When I run with argument -a:

prompt$ ALLTRAY_DEBUG=ALL alltray -D -a
AllTray 0.7.3dev+, from bzr branch alltray,
  rev-id <email address hidden>
Copyright (c) 2009 Michael B. Trausch <email address hidden>
Licensed under the GNU GPL v3.0 as published by the Free Software
Foundation.

[2009-07-16 13:20:08 CEST] INFO/MISC: Debugging subsystem setup
complete.
[2009-07-16 13:20:08 CEST] INFO/CL: Command line options parsed.
[2009-07-16 13:20:10 CEST] INFO/AH: Looks like we got win 0x00c37225

(alltray:26311): Wnck-CRITICAL **: wnck_window_get_pid: assertion
`WNCK_IS_WINDOW (window)' failed
[2009-07-16 13:20:10 CEST] INFO/AH: Win 0x00c37225 pid = 0
[2009-07-16 13:20:10 CEST] INFO/CL: Evaluating
alltray-internal-fake-process
[2009-07-16 13:20:10 CEST] INFO/CL: Actually processing arg
[2009-07-16 13:20:10 CEST] INFO/CL: Evaluating 0
[2009-07-16 13:20:10 CEST] INFO/CL: Actually processing arg
[2009-07-16 13:20:10 CEST] INFO/PROCESS: run_fake()
[2009-07-16 13:20:10 CEST] INFO/PROCESS: Process 0 now attached.
[2009-07-16 13:20:10 CEST] INFO/APP: Hey hey, creating a new Application
[2009-07-16 13:20:10 CEST] INFO/MISC: delete_pd_window()
[2009-07-16 13:20:11 CEST] INFO/APP: pid 8144 (gnome-terminal) is not
ours.
  Want pid = 0, ppid = 0, or pgid = 26311, have pid = 8144, ppid =
8143, pgid = 8142
[2009-07-16 13:20:11 CEST] INFO/APP: pid 25957 (claws-mail) is not ours.
  Want pid = 0, ppid = 0, or pgid = 26311, have pid = 25957, ppid =
3373, pgid = 25957
[2009-07-16 13:20:11 CEST] INFO/APP: pid 3523 (firefox-3.6) is not ours.
  Want pid = 0, ppid = 0, or pgid = 26311, have pid = 3523, ppid =
3522, pgid = 3522
[2009-07-16 13:20:11 CEST] INFO/APP: pid 9001 (gedit) is not ours.
  Want pid = 0, ppid = 0, or pgid = 26311, have pid = 9001, ppid = 1,
pgid = 8959
[2009-07-16 13:20:11 CEST] INFO/APP: pid 8959 (nautilus) is not ours.
  Want pid = 0, ppid = 0, or pgid = 26311, have pid = 8959, ppid =
3373, pgid = 8959

** (alltray:26311): WARNING **: Application.vala:97: Got PID 0; some
application is buggy!

########################

And when I do with argument -p it works as soon as I close the terminal
where the process is running. 

prompt$ ALLTRAY_DEBUG=ALL alltray -D -p 9001
AllTray 0.7.3dev+, from bzr branch alltray,
  rev-id <email address hidden>
Copyright (c) 2009 Michael B. Trausch <email address hidden>
Licensed under the GNU GPL v3.0 as published by the Free Software
Foundation.

[2009-07-16 13:23:19 CEST] INFO/MISC: Debugging subsystem setup
complete. [2009-07-16 13:23:19 CEST] INFO/CL: Command line options
parsed. [2009-07-16 13:23:19 CEST] INFO/CL: Evaluating
alltray-internal-fake-process [2009-07-16 13:23:19 CEST] INFO/CL:
Actually processing arg [2009-07-16 13:23:19 CEST] INFO/CL: Evaluating
9001 [2009-07-16 13:23:19 CEST] INFO/CL: Actually processing arg
[2009-07-16 13:23:19 CEST] INFO/PROCESS: run_fake()
[2009-07-16 13:23:19 CEST] INFO/PROCESS: Process 9001 now attached.
[2009-07-16 13:23:19 CEST] INFO/APP: Hey hey, creating a new Application

Nothing seems to happen but when I close the terminal the tray-icon
appears and it works ok. I hope this is useful info. Ask anything. Btw
I need kill -9 to kill alltray. But maybe that is normal behavior.

Martin