Cannot format partition to ext2

r69590, VBox 5.0.6.

Repro:

• attached a second IDE HDD to my VM in VBox as primary slave
• drive not visible in Explorer
• booted into usetup, formatted it as FAT32 (then exited so as not to actually install ROS on it)
• drive is now visible in Explorer -> RMB -> Format...
• set FS to EXT2, left everything else untouched (no drive label, no quick format)
• click Format button

What happens:

• filesystem is not changed, error in debuglog shown
• "allocation unit size" text input field disappeared in Format... wizard
• properties of the drive still say FAT32
• "unable to get file system of D:\" shortly shown on each bootup
• after reboot the FS is not recognized and drive is shown with cdrom icon, FS unknown

Attaching debuglogs from booting ROS and from the formatting action.