imho this is totally unrelated to #498686

I have ASUS A6Km (which has a crappy bios by the way and asus does not seem
to care at all)
My HDD is and IDE drive and in 2.6.18 it was /dev/hda some kernels later it
became /dev/sda (I amnot sure when this change happened, but I am sure it
was a 2.6.2x kernel).
Since 2.6.26-1-686 version -5 the hard drive is /dev/hda again.

Therefore /etc/fstab and /boot/grub/menu.lst need to be changed manually.

If you are using uswsusp, you also have to edit
and run
dpkg-reconfigure uswsusp

If you have some encrypted partitions as I have, it is a good idea to also
check out /etc/crypttab

This is very likely related to this in the changelog:
[ Bastian Blank ]
* Reenable SiS SATA support. (closes: #496603)

because my IDE bus is
00:02.5 IDE interface: Silicon Integrated Systems [SiS] 5513 [IDE] (rev 01)