I want you to notice AS's report in that thread : AS you didn't mention which kernel 2.6.38 you used. pclos1 and plos3 give a different result in my Pentium 4 : pclos1 reboots after shutdown whatever option I insert, pclos3 shuts down correctly if I use "noacpi" instead of "acpi=on". Theses options are also available at start of Live CD and installed version, with the F3 key.
This was already reported previously:http://www.pclinuxos.com/forum/index.php/topic,93164.msg782811.html#msg782811
And yes, I have downloaded and tested all pclinuxos-bonsai releases, all with the same results:
-rw-r--r-- 1 root root 284565504 Jul 16 02:19 /free_vm/pclinuxos-openbox-bonsai-2011.07.15.iso
-rw-r--r-- 1 root root 281866240 Jul 20 02:20 /free_vm/pclinuxos-openbox-bonsai-2011.07.iso
-rw-r--r-- 1 root root 276932608 Jul 22 10:24 /free_vm/pclinuxos-openbox-bonsai-2011.iso
-rw-r--r-- 1 root root 259178496 Jul 15 15:37 /free_vm/pclinuxos-openbox-bonsai-test-2011-06-19.iso
Maybe, you should look around some change around the followings:
apparently initscripts-8.99-22pclos2010 is installed in openbox-bonsai, but at least the script /etc/init.d/halt is not consistent with the mentioned package, don't know about the others files ...
Please, be clear that I report my results because I hope something could be found to solve the issue, but can't agree with you when you say the issue is related to ... kernel ... or... acpi ... because in that case all these things should arise also using the other PCLinuxOS flavor.
You can't say it's an ACPI issue, if this issue can't be replicated outside pclinuxos-openbox-bonsai, also you can't say it's a issue related to recent kernel because the very same kernels appear to work outside openbox-bonsai.
That's my strictly technical point of view. I'm still available to provide as much help as I can.