kgdb 'next' command crashes kernel during inter-VM kernel debugging

[Yuri]

I am trying to debug kernel in one VBox VM from another VBox VM using 
this howto: 
http://census-labs.com/news/2009/01/19/freebsd-kernel-debugging with the 
exception that on the target VM hint.uart.0.flags="0x90" is set instead.

It works, stops at breakpoints, etc. However, kgdb command "n" (next) 
causes target to reboot.

Device /dev/cuau0 is used for the serial port. On the host it goes 
through the local socket /tmp/com_1
All with FreeBSD 10 (trunk) amd64, virtualbox 4.2.16

Yuri