After run "startx" I get only NAUTILUS screen

Virtual BOX
Oneiric Server 32
booting perfect into text mode
after running "starx" I get full screen with menu from nautilus...nothing else, no lunch bar, nothing...
Start happening after trying to install VBOX guest additions

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: nautilus 1:3.1.4-0ubuntu2
ProcVersionSignature: Ubuntu 3.0.0-8.10-generic 3.0.1
Uname: Linux 3.0.0-8-generic i686
Architecture: i386
Date: Fri Aug 12 11:45:53 2011
ExecutablePath: /usr/bin/nautilus
InstallationMedia: Ubuntu-Server 11.10 "Oneiric Ocelot" - Alpha i386 (20110811)
ProcEnviron:
 LANGUAGE=pt_PT:
 LANG=pt_PT.UTF-8
 SHELL=/bin/bash
SourcePackage: nautilus
UpgradeStatus: No upgrade log present (probably fresh install)