I have also reported it to Oracle, but not through the public tracker - through my company's Java SE support contract. The response was that Java is only supported in a very restricted list of Hypervisors:
Oracle JDK 7 and JRE 7 Certified System Configurations (down the bottom)
Effectively since VirtualBox doesn't support OS X higher than 10.6, there's no way to reproduce the bug on a platform Oracle actually supports.
I was unaware of the safe mode replication case. I'll try that angle and see what happens 