Hi,
I'm quite interested in this thread, too.
I experience similar problems with two VMs that run pfSense's FreeBSD on a Windows XP Pro and a Mac Os X (10.4) VirtualBox host environment. I'm experimenting with these VMs for severals days now inside my VLAN environments without any success.
Finally I booted a "physical machine" (PM) with the Live-CD of pfSense to test if the problem resides within the VMs, pfSense itself, Windows, OSX, the HP switches or whatever...
As I have completed the setup and connected all as it should I could connect the Live-CD PM successfully to any possible VLAN in my network.
After the PM test I transfered the EXACTLY same configuration to my VMs but had no success at all with this.
So my conclusion is that the problem must be:
* Somewhere within the VMs host emulation of the NICs, as both (the Windows and the Mac) hosts fail to transport my packets correctly. So, I also don't think it's an Windows Problem (although I've read many threads on this) with VLAN incompatibility.
* OR sth due to an incompatibility of FreeBSD with the "em0" NICs of VirtualBox
I'm very excited how this thread develops and if we can find a solution on this.
Good luck for your testing!
;-)
- Michl