(k)ubuntu: boot interrupted?

Question

GRUB

There is an ASUS Rampage 2 Extreme system with a PATA/eSATA JMicron JMB36X controller, and the following devices:
PATA:
1. Seagate Barracuda
2. Pioneer DVD-RW
SATA:
1. Intel SSD 320
Kubuntu 11.10 64-bit (3.0 kernel) is installed on the SSD , when installed, the barracuda was physically disabled.
Problem: I connect barracuda to ATA, to a common interface with an optical drive (on rampage 2 there is only 1 PATA port), I start kubuntu - the download is interrupted almost immediately after jmicron_pata initialization (judging by dmesg), while busybox starts.
I turn off the barracuda (the optical drive remains) - the system starts up normally.
In both cases, no explicit error notifications are visible in dmesg, no messages are displayed when starting busybox.
Just in case, I shamanized with the master / slave and switching the modes of PATA and SATA controllers (IDE, AHCI, RAID) - the result is exactly the same - the system crashes somewhere during the initial initialization, if a second PATA device is connected.
Interestingly, before that, Slackware64 13.37 was installed with kernel 2.6.37.6, which worked without any problems with hardware at all (as well as Windows 7 64).
In general, what is my problem? Maybe JMicron is not to blame here?

Answer 1

Found your problem in dmseg:
Command line: BOOT_IMAGE=/boot/vmlinuz-3.0.0-12-generic root=/dev/sda3 ro quiet splash vt.handoff=7
change root=/dev/sda3 to root=/dev/sdb3

1. Boot from livecd
2. mount ssd
3. go to /boot/grub.conf (can't remember exactly)
4. find and rewrite the specified line

should work after reboot.