wake-up after S3 suspend on Asus M4A77T

Hello,

My system (openSUSE 11.4) does not wake up after suspend to ram (S3).

Here the commands, that work on many other systems with Asus-boards, but
not on the M477T:

echo 0 >/sys/class/rtc/rtc0/wakealarm
date -d “now + 5 minutes” +%s >/sys/class/rtc/rtc0/wakealarm
s2ram -f

Instead of waking up automatically after 5 minutes, I must press the
power button to wake up the system.

It’s perhaps a kernel issue, because when specifying the wake-up time
directly in the bios, it works.

Where could be the problem?

What is the experience of other users of the M477T board?

TIA for any hints!
Peter