Strange acpi problem

[Nicolas]

Hello,

I'm using FreeBSD 9-Current with Gnome 2.30 and i have strange problem 
with "upowerd", it consume 66% or 94% of my cpu.
When i type "dmesg" on the terminal i have this message from FreeBSD:

acpi_ec0: EcRead: failed waiting to get data
ACPI Exception: AE_NO_HARDWARE_RESPONSE, Returned by Handler for 
[EmbeddedControl] (20100428/evregion-588)
ACPI Error (psparse-0633): Method parse/execution failed 
[\\_SB_.BAT0._BST] (Node 0xc6f3e420), AE_NO_HARDWARE_RESPONSE

It's strange because it does not happen all the time, someone has this 
acpi problem ?

Thank you in advance,
Nicolas.