After define partitions installation crash unetbootin xubuntu

[Fabian]

I'm using unetbootin because the install CD doesn't work fine, make a false io problem from CD and the CD is fine.

Booting with unetbootin doesnt work fine because a unmount /cdrnom happens...so I start live test and unmount, then this error happen

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: ubiquity 2.8.7
ProcVersionSignature: Ubuntu 3.0.0-12.20-generic 3.0.4
Uname: Linux 3.0.0-12-generic i686
ApportVersion: 1.23-0ubuntu3
Architecture: i386
Date: Sat Jan 14 00:39:52 2012
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)