[lubuntu] Updating Lubuntu Guest crashes VirtualBox

I'm trying to wrap my head around this issue and it's past me. I'm not sure if this is an issue with Lubuntu or VirtualBox, but more than likely, it's both.

I tried installing Lubuntu 64-bit desktop through VirtualBox (Host is Windows 7 64-bit), over and over again, and it kept crashing. Eventually, I found a solution. I disabled the 'download updates as I install' feature, and it worked like a clock. The install would finish, everything would be grand.

Then, upon first boot, it would ask to install updates. Natch. So of course I installed updates. And it'd crash again.

I want to be clear, this is not the operating system crashing. It's VirtualBox. Perhaps I'm just an idiot, but I didn't even know this was possible. I thought this would be like a laptop spontaneously melting.

Actually, that almost happened to me once.

Anyway, the only way to get the VM to work again, was by restarting everything, which I did by deleting the hard drive, and building a new one, before reinstalling Lubuntu. But this time I did create a Snapshot of a fresh, pre-update install. Before trying to update again, so when it crashed, I could go back to the last time it actually worked.

I tried a few different things after this. On a recent attempt, I thought it updated successfully, but I think it failed to update everything, since it wasn't long before my attempts to install more packages faced me with an update option. Then it crashed.

I know what you're thinking, you want details. Here's a copy of the log file, and a screenshot from a millisecond before the crash, that VirtualBox captured. Major clue in that screenshot, I assume.

Any ideas?