I am running ubuntu 9.10 two ways: (a) as the host OS on one machine I will call ``Machine A'' (or just "A"), and (b) as a guest OS (in Oracle VM virtualbox 3.2, upgraded today from sun virtualbox 3.1) on another machine I will call ``Machine B'', (or just "B"). The host OS of Machine B is Win XP Pro. On A, I have installed sun virtualbox, and for a while that worked well. On B, within the guest (ubuntu), I had previously installed sun virtualbox 3.1, but had not yet used it, so I uninstalled it, and then installed the latest Oracle VM virtualbox 3.2. (perhaps I'm crazy, but I would like to try a ``virtual within a virtual''). In both cases, the ``upgraded'' version of virtualbox now does not work under ubuntu 9.10. It fails to start my guest OS in each case. On A, I tried to restart my guest Win XP machine, while on B, I tried to install a Win 3.1 guest. In both cases, I am instructed to install DKMS. I've done so, to no avail.