The problem is solved on my machine - I replaced the SATA cabling with better quality Akasa latch cables instead of the cheap cables that come with the motherboards. So far I have installed and run Ubuntu/Hardy and installed Gentoo (on another partition) and compiled X/Gnome with no problems. The machine has been rebooted several times and has not frozen once.
So I can confirm that one possible cause of the error -
The problem is solved on my machine - I replaced the SATA cabling with better quality Akasa latch cables instead of the cheap cables that come with the motherboards. So far I have installed and run Ubuntu/Hardy and installed Gentoo (on another partition) and compiled X/Gnome with no problems. The machine has been rebooted several times and has not frozen once.
So I can confirm that one possible cause of the error -
[ 231.478375] ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x2 frozen
Could be poor quality cabling.
Googling around problems with cheap SATA cabling are very common.