You can capture the boot log is as follows:
1. Add a serial port to your virtual machine. Configure it to send its output to a file, say, serial.log.
2. Power on the VM to grub, remove quiet from the kernel command line, and also add the following:
earlyprintk=serial,keep
3. Proceed to boot the OS.
Probably nothing will display on the screen, but you should instead get a very nice serial.log containing the early boot messages. Feel free to attach it as a file if you'd like us to look at it. (Please don't copy and paste anything more than 10-20 lines of excerpt, though... Spare everyone's inboxes by attaching the file: Choose Use advanced editor in the upper-right corner of the compose window, then choose the Browse button which appears below.)
Cheers,
--
Darius