ASUS M3N standby resume regression in 2.6.x -- works under 2.4.x

Hi,

In my ASUS M3N laptop, Centrino based, standby (S1) works fine with 
linux 2.4.x, x>~24, but fails for all 2.6.x series.

In runlevel 1, even with all modules unloaded (but the filesystem 
modules and usbcore, I can't remove it), the system enters standby upon 
executing
   echo 1 > /proc/acpi/sleep
but after pressing the power button to resume the PC hangs.
Standby works fine under linux-2.4.x, even under runlevel 5.

Upon resume, the system becomes blocked, and nothing is written to the 
logs, so I can't give more details other that the ones written to the 
screen:

Stopping tasks:===|
hwsleep_0315[28215] acpi_enter_sleep_state: Entering sleep state [S1]
Back to C!
ACPI: pci interrupt 0000:00:02:0[A] -> GSI 11 (level, low) -> IRQ 11

The hwsleep_0315[xxx] message can vary, depending on the modules loaded, 
the xxx can be 28 or 22.
With all usb modules loaded the message says
   PCI: setting latency time of device yyyy to 64
where yyy corresponds to the threee 
   USB Controller: Intel Corp. 82801DB USB

So, somehow the system starts resuming (the LCD turns on after pressing 
the power button to resume), but hangs after that. Under 2.4.x any 
button starts standby resume, but under 2.6.x only the power button is 
responsible; curiously, under 2.4.x the power button shouldn't be used 
to resume, because it generates two acpi events.

What else can I do to help you helping me? :)

I attach the boot messages and lspci output.The kernel config file, and 
the asl can be found at 

http://www.fe.up.pt/~jcard/acpi/2.6.10.config
http://www.fe.up.pt/~jcard/acpi/M3N-BIOS-0203A.asl

To further complicate matters, ASUS has released a new BIOS, 0206A, but 
under that BIOS standby does not work even under 2.4.x. That BIOS asl 
can be found at http://www.fe.up.pt/~jcard/acpi/M3N-BIOS-0206A.asl

Thanks,
Joao