Just a simple post, a sharing today. If you are VirtualBox lover, you might use Snapshot feature provided by VirtualBox to utilize your productivity, just try to create your base VM using VDI or VMDK format instead. What if you decided to go to VHD format with snapshots? You might face situation below:

 I received the message "Parent UUID {00000000-0000-0000-0000-000000000000} of the medium 'C:\XXXXX/{6f6bed49-0fe6-4458-612-093ddfb81be4}.vhd' does not match UUID {05872920-d882-404a-a034-161792b554c7} of its parent medium stored in the media registry 

But I didn't face any related problems if I using VDI or VMDK format virtual disk.
However, my current version of Virtualbox is 4.2.18. :)

Link of tool to help you convert your VHD to VDI:  CloneVDI tool - Discussion & Support from VirtualBox forum.