I also have trouble trying to test my remasters in VirtualBox, so you're not alone. However, I can usually get it to work by pressing an arrow key to stop the countdown and then going back to the top entry, pressing F3 and selecting "Safe Options".
However, that's in KDE. If the Windows desktop intercepts F3 you might need to find another way, or find a way to disable the interception.
Pclos hasn't built VirtualBox for a while now, so it's possible the video driver doesn't match the current version of VB.
On the other hand, I believe many packagers use it a lot, so there might be another reason altogether.