Since Debian Squeeze has choosen kernel 2.6.32 as the main release, I built the lastest released stable kernel 18.104.22.168 with some modules. It has been up and running for about 1 week now and quite stable.
It is a u-boot kernel so you need the latest bootloader from Shihsung. Due to the needs of setting "R/W multiple sector transfer" to the harddisk using hdparm, I decided to use the old IDE driver. So you need to change the kernel boot command to root=/dev/hda1.
Thanks Shihsung for the patch for 22.214.171.124 which I was based on.
(RTC is fully working now! If you downloaded before 2010-7-16, please download again)http://downloads.buffalo.nas-central.org/Users/ramp/