Error saving VM's state on FreeBSD 8.x in headless

[Alexandr Krivulya]

Hello,
I have problems with saving state of VM on 8.x with virtualbox-ose-3.1.2_1, when vm running in 
headless mode:

$ VBoxManage controlvm WIN2003STD savestate
VirtualBox Command Line Management Interface Version 3.1.2_OSE
(C) 2005-2009 Sun Microsystems, Inc.
All rights reserved.

0%...10%...20%...30%...40%...50%...60%...70%...80%...90%...
Error: failed to save machine state. No error message available!

There is no any problems, when running vm in normal mode. On FreeBSD 7.2 saving state works fine on 
both normal and headless mode. Thx!