Comment 0 for bug 1087622

I have Ubuntu 12.10 32bit installed (upgraded in october from 12.04), running smothly on a Lenovo Thinkpad Edge with linux kernel 3.5.0-19. I upgraded to 3.5.0-20 this morning and the laptop don't wan't to boot anymore (purple screen without Ubuntu logo, than blackscreen frozen, no activity noise from drive). Reverting to 3.5.0-19 is okay.
I tried to launch "ubuntu-bug linux" but it tries to report a bug against 3.5.0-19 (of course...), so I attached dmesg.0 which should be the dmesg from the failed 3.5.0-20 boot try, I my understanding is okay.
How can I collect more infos about this bug, considering it's not booting? Thanks for any help.