vboxmanage controlvm <vm> poweroff hangs

[Scrub Jay]

I start several XP guests via Headless, then "controlvm poweroff" and "snapshot <vm> restorecurrent" before repeating the sequence. About every 200-300 cycles, the vboxmanage controlvm <vm> poweroff will hang, and continually spit errors to the log per the attached. I read in an old forum that concurrently powering off multiple guests can cause a hang, so I've wrapped mine in a lock that ensures 2 second delays between poweroff's of different guests. That does not eliminate the problem.

[Scrub Jay]

This problem continues with version 4.2

[Jozue7]

I have same problem with version 4.3.6 and it's not depend on guest OS(it's occurs on Linux32/64, FreeBSD, Solaris, ...) or host types: Linux and MacOS. I use simultaneously 5 guest machines and sometimes it's occurs.

Where can i get VirtualBox with debug symbols to produce backtrace. And which other information do you need?

[Jozue7]

GDB output of VBoxHeadless from freezed machine. VBox:4.3.6, OS:ubuntu64_12_04 LTS

[Jozue7]

GDB output of VBoxManage from freezed machine. VBox:4.3.6, OS:ubuntu64_12_04 LTS

[Jozue7]

Added attachments from GDB(VBoxHeadless.txt, VBoxManage.txt). It was captured when VBoxManage was hanged.

[Jozue7]

When i call second time to poweroff machine i get error: /usr/lib/virtualbox/VBoxManage controlvm 61f6bcb4-78b0-11e3-9b18-441ea15924c0 poweroff

VBoxManage: error: The virtual machine is being powered down
VBoxManage: error: Details: code VBOX_E_INVALID_VM_STATE (0x80bb0002), component Console, interface IConsole, callee nsISupports
VBoxManage: error: Context: "PowerDown(progress.asOutParam())" at line 222 of file VBoxManageControlVM.cpp