Marshmallow in VirtualBox:installation stuck on GRUB

I'm trying to install android-x86-6.0_20160129.iso in VirtualBox but the installation get stuck at Do you want to install boot loader GRUB

Some background:

• The VM was created from the Ubuntu 32-bit (x86) VirtualBox template
• The VM has 1 core + 3096 MB RAM
• Video memory: 32 MB
• PAE/NX enabled
• Hardware virtualization: both VTx and nested pagination enabled
• Graphics acceleration: disabled (both 2D and 3D)
• Storage: 64 GB attached to IDE virtual controller (was SATA before: makes no difference)

I've already tried all the "standard" VirtualBox procedure (PAE yes/no; SATA/IDE; no soundcard; no USB; graphics accel. yes/no).

I also tried run the Live CD in VESA mode: like this it starts, but I'd still prefer to install it.

First, select Create/modify partition:

Then create 2 partitions:

• Create a small (100m) first primary partition for grub. Set the bootable flag. Write changes.
• Create an extended (logical) partition for the rest, and install android on the 2nd. Grub will go automatically to the 1st one. Write changes.

Just adding my 2 cents, on what I think is happening:

Actually from a bit of experimentation it's not the presence of 2 partitions that allows Grub to proceed it's the "Create/Modify permissions" that you need to get into first to create a GPT partition table before you can format the partition. (That's why manual partitioning also worked for Dr. Gianluigi Zane Zanettini in the comments of the originally accepted answer).

What actually seems to be happening is that if you don't create the partition table, when you come to the formatting stage where it asks you to format the partition (EXT4, EXT3, etc), the installer seems to say that it's successful, when actually it hasn't happened because the GPT partition table doesn't exist. So when it asks you to install grub it tries to install grub onto an unformatted partition ... and fails silently.

If you go to "Create/Modify Partition" and create a "New" single partition (accept the defaults creating a single partition), "Write" "Quit"; and then go to format the partition after as the next step, Grub will get installed and the installation will proceed as normal.

(Emphasis on the single just to show that even a single partition will work.)

NB: I haven't managed to get the GUI to run for Android x86 (android-x86-6.0_20160129.iso), but at least it seems to boot - meaning it passes through the grub installation and i get a shell prompt.