We have done enough testing to conclude that VirtualBox v4.1.4 has a problem with how our code kicks into protected mode. We tested on several host CPUs and various host OSs with the same result: OS locks up shortly after entering protected mode. We tested the same OS image with VMWare Player, VMWare Workstation, and VMWare Fusion and it ran flawlessly every single time.
Our test image is 32K. Small enough to post here or send via e-mail. Please let us know if wish to look into this problem. Thank you.
Sincerely,
/Antonio C.