Power down not working

[patrick]

FC3 RC1 doesn't shutdown my computer. It is working with FC1 on another 
partition. I think I have a pretty common hardware

Here is the details:

Elite K7S5A + Athlon XP 2000 + 2 Seagate IDE HD

acpid is working before shutdown:

root      2007     1  0 20:48 ?        00:00:00 /usr/sbin/smartd
root      2017     1  0 20:48 ?        00:00:00 /usr/sbin/acpid

Last message when shuting down:

umounting filesystems            [OK]
halting system ...
md: Stoping All md devices
md: md0 still in use
Shutdown: hdb
Shutdown: hda
Power down
acpi_power_off called


The FC3 was installed with RAID and LVM activated (choose RAID in 
anaconda install, RAID partition then assign it to a LVM volume which 
contains / and swap). The boot partition is not configured in RAID (hdb1)

Is this due to the partition configuration ?