uuid error on VB 4.2.28 r97679

[tmel173]

I have a virtualbox on ubuntu 12.04 version 4.2.28 r97679 and having an issue deleting a uuid from vmdk file on an external drive. the error is below but the backgorund is that I tested a vmdk that was on an external hdd first before copying it to an internal disk successfully. I have copied it to the hdd but I received an eerror telling the uuid was already existing so a quick google pointd me to purge the uuid before pointing from the external hdd first because its embeded on the VB. The trouble now is for some reason the uuid can not be removed. when I do " vboxmanage closemedium disk b80016c6-3e13-4b56-9b7a-64b458c9f146 --delete " I get the error below :

vboxmanage closemedium disk b80016c6-3e13-4b56-9b7a-64b458c9f146 --delete
VBoxManage: error: Cannot close medium '/media/TOSHIBA EXT/Ubuntu-disk1.vmdk' because it has 1 child media
VBoxManage: error: Details: code VBOX_E_OBJECT_IN_USE (0x80bb000c), component Medium, interface IMedium, callee nsISupports
VBoxManage: error: Context: "DeleteStorage(progress.asOutParam())" at line 1166 of file VBoxManageDisk.cpp
VBoxManage: error: Failed to delete medium. Error code Unknown Status -2135228404 (0x80bb000c)
VBoxManage: error: Cannot close medium '/media/TOSHIBA EXT/Ubuntu-disk1.vmdk' because it has 1 child media
VBoxManage: error: Details: code VBOX_E_OBJECT_IN_USE (0x80bb000c), component Medium, interface IMedium, callee nsISupports
VBoxManage: error: Context: "Close()" at line 1175 of file VBoxManageDisk.cpp

Any ideas on how to purge thi uuid so that I can use the vmdk on my internal disk instead of the one on my external hdd ?

[mpack]

As the error message implies, you have to get rid of the child media first.

You can't just copy VirtualBox files around, and copying media with snapshots is especially unwise. VirtualBox registers the UUID and path of all media and VMs you tell it about. If you want to move things around you need to unregister them first. Howto: Move a VM.