djohnston, I have no experience with virtualbox, but judging from this url it looks like the KNOPPIX file needs to be uncompressed.
The URL you're pointing to has links for compressed and uncompreesed disk images. (I had to delete the embedded link in order to post this.) My problem is, (now was
), booting from the iso file. I tried the latest KNOPPIX, which of course, has the KNOPPIX image file in the iso. It boots just fine. I then tried to boot from the dsl-4.4.10.iso and from the dsl-4.4.10-initrd.iso with no success.
However, the solution to my problem was very simple. Since mrmango wasn't forthcoming with any information, the problem was that VirtualBox had assigned a SATA hard drive to the VM. After deleting it and creating a PATA drive, the 4.11.RC1 iso booted quickly to the desktop using the default options. I don't know if this has ever come up before, but that was the solution in my case.