I have attached two log files, it's the same VM, one where I let it boot without intervention and it just stays on a black screen with a blinking _ and 100% CPU on one core. It also appears that the OS you want to boot using the boot menu (F12) may fail. It doesn't matter which host or Guest you have. It is reported for version 3.2.4, but I think this problem exists in all versions where more controllers are available. The first reply (second post) is the vital one. Here is one of the examples, though the issue describes something else too: The first detected hard drive is tried, but never another if that one fails.
There is no way to set the controller priority in the VM settings for booting the VM. When you have several hard drives set in your VM and the actual boot disk is SATA or on any other controller than IDE, while you have an IDE hard drive attached, it will fail to boot.
