Installation from USB is not able to recognize the partition, so it freezes.

Binary package hint: unity

Installation from USB is not able to recognize the partition, so it freezes.
My PC is:
N61Jq Asus - Intel Q720m
8GB DDR3 1333
Ati radeon 5730m

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: nautilus 1:2.32.2.1-0ubuntu7
ProcVersionSignature: Ubuntu 2.6.38-5.32-generic 2.6.38-rc6
Uname: Linux 2.6.38-5-generic x86_64
Architecture: amd64
Date: Mon Feb 28 00:47:09 2011
ExecutablePath: /usr/bin/nautilus
LiveMediaBuild: Ubuntu 11.04 "Natty Narwhal" - Alpha amd64 (20110227)
ProcEnviron:
 LANGUAGE=es:en
 LANG=en_US.UTF-8
 LC_MESSAGES=es_ES.UTF-8
 SHELL=/bin/bash
SourcePackage: nautilus
XsessionErrors: (nautilus:10554): GConf-CRITICAL **: gconf_value_free: assertion `value != NULL' failed
usr_lib_nautilus: nautilus 1:2.32.2.1-0ubuntu7evince 2.32.0-0ubuntu10brasero 2.32.1-0ubuntu2file-roller 2.32.1-0ubuntu3gnome-disk-utility 2.32.1-0ubuntu4nautilus-sendto 2.32.0-0ubuntu1nautilus-share 0.7.2-14ubuntu1ubuntuone-client-gnome 1.5.5-0ubuntu2ubuntuone-client-gnome 1.5.5-0ubuntu2ubuntuone-client-gnome 1.5.5-0ubuntu2totem 2.32.0-0ubuntu9