I can not boot ubuntu unless I disconnect all devices and cables

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http://askubuntu.com – Few days before, I have upgraded my OS from 12.04 to ubuntu 12.10 (quantal) 64-bit. Ever since that, when I try to boot my notebook with any cable connected to it, the screen just remains black and nothing happens and I have to reboot my notebook by force(holding power button). With no cable connected, ubuntu loads just fine and than I can connect everything and there is no problem. I guess, that it freezes before the kernel is loaded, because when I tried to reboot the computer using alt + screen + b, nothing happened.I was experiencing these difficulties even on the previous version, but ju (HowTos)