I thought I would mention this on the forum as well. I created a bug report on this a few weeks ago: https://www.virtualbox.org/ticket/16735
I've seen some comments in other posts that indicate that others have seen this same problem, but I haven't seen any kind of answer or resolution to this specific issue.
The issue is pretty easily reproducible for me, on different hardware and host OS.
I'm can try things out and test potential fixes if that would help.
Jeff