VirtualBox Kernel panic

Question

I have been running VirtualBox for some weeks with no problems. Now when I start it up I get this

Kernel panic - not syncing: Attempted to kill the idle task!

atkbd serio0: Spurious ACK on isa0060/serio0. Some program might be trying to 
              access hardware directly.

For reference the ISO is Slacko Puppy Linux.

I tried removing and re-adding the hard disk as has been suggested.

Solution

I tried loading Ubuntu rather than Puppy and it worked. However before booting Ubuntu also put out an error

SMBus base address uninitialized - upgrade BIOS or use force_addr=0xaddr

Looking up that error led me to a blog post that suggests

reset the VM and after selecting the language just press F6 and press enter to select acpi=off then ESC to go back. This should do it.