Try from the commandline:

shutdown -h now

or

halt

or

poweroff

Obviously this won't solve your problem completely (as ideally you want to be able to do it via the GUI) but at least it may help you save your network config... Bottomline though is that AFAIK it should just work OOTB. I suspect that it's something to do with ACPI, it may be worth having a bit of a goolge around Debian, ACPI and VirtualBox.

And yes your networking config should work, although I'd be inclined to use Conconsole to configure your static 'host only' connection (you can configure which interface Confconsole uses via the conf file in /etc somewhere) and let the NAT be auto assigned IP via VBox's built-in DHCP

It's been a while since I used any desktop virtualisation but I don't ever recall having these sort of problems... I can't help but think that perhaps there is something wrong with the VM image you are using??

Perhaps you could try manually editing the network config yourself (sorry I don't have step-by-step OTTOMH). If it still doesn't stick then I have no idea... Perhaps just try reinstalling from ISO??

It definately sounds like the changes to the (virtual) harddrive aren't being saved, but the fact that there aren't any error messages warning you of this seems very strange indeed. Have you tried saving/creating other files on the server to confirm that our theory is correct (you can use the touch command to create empty files, or nano to create a text file which you can put some text in) to test?

Out of curiosity have you tried installing something else (other than TKL) to a VM and see how that acts and if it is the same? At least then you can see whether the strangeness is something to do with TKL or VirtualBox (or whatever VM software you use - sorry I didn't read back through the thread to check). Or perhaps even OS related...?

I just thought I'd test this out for myself and see if I could reproduce your issue, but I can't.

Here's some info about my setup and the steps I followed so we can perhaps see where the differences are:

• VirtualBox (v4.2.4r81684) freshly downloaded and installed on Win7 (Pro SP1)
• TKL LAMP VMDK build (turnkey-lamp-12.0-squeeze-x86.vmdk.zip) freshly downloaded
• Contents of zip extracted (using Win7 default right-click 'extract all' and copied) to C:\Users\Jed\VirtualBox VMs\TKL LAMP\ (ie vHDD is C:\Users\Jed\VirtualBox VMs\turnkey-lamp-12.0-squeeze-x86-vmdk\turnkey-lamp-12.0-squeeze-x86.vmdk)
• Used the VBox 'New' VM wizard to create a new VM:
  • Set the OS to Linux > Debian
  • Selected 'use existing vHDD' - browsed to the extracted disk image (path as above)
  • Accepted all other defaults
  • Once completed, set networking to 'Bridged'
• Started new VM
• Input all firstboot info (skipped TKLBAM setup and security updates)
• Set a static IP from ConfConsole and manually configured my DNS (I need to fix my DHCP server as it is giving the wrong DNS info...)
• Exited out of ConfConsole
• Ran apt-get update && apt-get upgrade
• Created a test file in /root (touch testfile)
• Took a snapshot (in case I experienced same as you - I intend to use this server  for some other testing)
• Shutdown VM (halt)
• Started VM again (from VBox UI)
• Confirmed that everything is as it should be (confconsole still had my static network settings there and ls showed that testfile was there)

Other than confirming your experience of VBox 'send the shutdown signal' not working and it being quite slow (I'm used to running OVZ containers on my Promox server) it all seemed to go well and acted as I would have expected it to.

So I'm not really sure what is happening for you. To double and triple check I started and stopped it multiple times creating testfiles as i went and they were all there...