help! vbox4.0.4, got "guru meditation" error

[brooze wang]

My host OS is win7, and guest OS is ubuntu Lucid. Vbox version is 4.0.4.

Now the guest os always stop at "'initrafs>" command line prompt after vbox manager report a message "guru meditation". and i has no any idea on how to recover it.

The context while vbox report this error is: I start and keep the guest OS running, then there is a USB stick plugged on the host. I remember that the USB device being detected by the vbox but failed to assigned to the guest. This detection/assignment action automatically happen endless till the vbox report "guru meditation" error.

The log file for this guest OS can be see at attachment.

Lucid-2011-05-05-09-39-41.log.tar.gz

unpack it to get the 192KB size file

(31.67 KiB) Downloaded 13 times

pls help me. It block me for serval days.

[brooze wang]

do i post to wrong forumn? so dispointted no any clue has received.

[brooze wang]

For more hint. I found it was linux boot failure after google. Following is the boot message:
"
mount: mounting /dev on /root/dev failed: No such file or directory
mount: mounting /sys on /root/sys failed: No such file or directory
mount: mounting /proc on /root/proc failed: No such file or directory
Target file system doesn't have /sbin/init
No init found. Try passing init= bootarg

Busybox v1.13.3 (Ubuntu 1:1.13.3-1ubuntu11) built-in shell (ash)
Enter 'help' for a list of built-in commands
(initramfs) _
"

Can i defer from 'Busybox v1.13.3 (Ubuntu 1:1.13.3-1ubuntu11) built-in shell (ash)' sentense that now the failed ubuntu version is ubuntu11?
if answer is 'yes', then i think it was the updation from ubuntu 10.04 to ubuntu 11 that undergo with my careless permission and failed to boot after updating.