(natty/nvidia) Xubuntu freezes randomly on boot and shutdown

[yesint]

Binary package hint: xfce4

When booting Xubuntu randomly freezes. It shows logo screen and then hangs forever until hard reboot. On shutdown it also sometimes freezes forever with black screen. In both cases keyboard is not functional - I can't switch to console. These problems are not systematic at all - just random.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: xfce4 (not installed)
ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic x86_64
NonfreeKernelModules: nvidia
Architecture: amd64
Date: Fri May 20 18:08:15 2011
InstallationMedia: Xubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427)
ProcEnviron:
 LANGUAGE=en_US:en
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: xfce4
UpgradeStatus: No upgrade log present (probably fresh install)

[yesint (yesint4)]

The problem is in plymouth - when I disabled it in grub the problem has gone for me.

[dino99 (9d9)]

outdated report & no more maintained distro; please send a new one if that issue still exist (using ubuntu-bug)