Virtualbox doesn't recognize anymore a virtual machine.

Binary package hint: virtualbox-ose

After having added shared folder, started the machine, and done some update inside it using apt-get, closing correctly the machine I'm not able to restart it.
Virtualbox write the following.

Could not load the settings file '/home/sources/.VirtualBox/Machines/BT-ubuntu/BT-ubuntu.xml'.
Cannot convert settings from version '1.10-linux'.
The source version is not supported.
Result Code:
VBOX_E_XML_ERROR (0x80BB000A)
Component:
VirtualBox
Interface:
IVirtualBox {3f4ab53a-199b-4526-a91a-93ff62e456b8}

I have restarted my Ubuntu.
The problem is not solved.
I have another machine that works correctly using the same Virtualbox application.

ProblemType: Bug
Architecture: amd64
Date: Wed Nov 10 14:01:20 2010
DistroRelease: Ubuntu 9.10
Package: virtualbox-ose-qt 3.0.8-dfsg-1ubuntu1.1
ProcEnviron:
 SHELL=/bin/bash
 PATH=(custom, no user)
 LANG=en_US.UTF-8
ProcVersionSignature: Ubuntu 2.6.31-22.60-generic
SourcePackage: virtualbox-ose
Uname: Linux 2.6.31-22-generic x86_64
VirtualBoxOse.DpkgList:
 rc virtualbox-3.2 3.2.0-61806~Ubuntu~karmic Sun VirtualBox
 ii virtualbox-guest-additions 3.0.8-1 guest additions iso image for VirtualBox
 ii virtualbox-ose 3.0.8-dfsg-1ubuntu1.1 x86 virtualization solution - base binaries
 ii virtualbox-ose-qt 3.0.8-dfsg-1ubuntu1.1 x86 virtualization solution - Qt based user
 ii virtualbox-ose-source 3.0.8-dfsg-1ubuntu1.1 x86 virtualization solution - kernel module