It looks to me like you've been bitten by this bug:
https://launchpad.net/distros/ubuntu/+source/linux-source-2.6.15/+bug/26119/+index
If you do a 'hdparm /dev/hda' you should also likely notice that "using_dma = 0 (off)". That seems to be the other symptom of this problem.
It looks to me like you've been bitten by this bug:
https:/ /launchpad. net/distros/ ubuntu/ +source/ linux-source- 2.6.15/ +bug/26119/ +index
If you do a 'hdparm /dev/hda' you should also likely notice that "using_dma = 0 (off)". That seems to be the other symptom of this problem.