got a crash notice just after installing new version (I am a new Linux user)

[Wayne Chapman]

Binary package hint: ubiquity

crash notice just after installing new distro

ProblemType: Crash
Architecture: i386
DistroRelease: Ubuntu 9.04
ExecutablePath: /usr/lib/ubiquity/bin/ubiquity
InterpreterPath: /usr/bin/python2.6
MediaBuild: Ubuntu 9.04 "Jaunty Jackalope" - Release i386 (20090420.1)
Package: ubiquity 1.12.12
ProcAttrCurrent: unconfined
ProcCmdline: /usr/bin/python /usr/lib/ubiquity/bin/ubiquity --only
ProcEnviron:
 LANGUAGE=
 PATH=(custom, no user)
 LANG=en_US.UTF-8
PythonArgs: ['/usr/lib/ubiquity/bin/ubiquity', '--only']
SourcePackage: ubiquity
Title: ubiquity crashed with IOError in chroot_setup()
Uname: Linux 2.6.28-11-generic i686
UserGroups: