Until proven otherwise, this is very likely a dmraid bug.
If you can boot into the system, could you please run the following command, and report back with their output?
sudo dmraid -s
In addition, when attempting to boot 2.6.28-11-generic, do you get dropped to a prompt? If so, please run the command "dmraid -ddd -ay" and report back with the output.
Until proven otherwise, this is very likely a dmraid bug.
If you can boot into the system, could you please run the following command, and report back with their output?
sudo dmraid -s
In addition, when attempting to boot 2.6.28-11-generic, do you get dropped to a prompt? If so, please run the command "dmraid -ddd -ay" and report back with the output.
Thanks.