Hi,
I have been hitting the wall for few hours, but could not figure out how to do the following:
I have been running VC 6.1 fine on my ESXi 4.1, but had to upgrade ESXi to version 5.0. then problems arise, because I was able to upgrade all VMWare Tools on all machines, except on Vyatta 6.1 (linux-headers problems).
Ok, let's go another way.
I grabbed VC 6.2 LIVE CD, and installed new virtual machine (image-install).
Because I have hundreds of rules (config.boot = 39kB), AND mostly because Vyatta's function to show configuration as set of config commands does NOT work (I only get first hundred or so commands, others are lost), so I decided to simply:
- get old config.boot from VC 6.1
- copy it to VC 6.2
- adjust MAC addresses and encrypted passwords
- save new config.boot
- reboot and...I should get running system
My procedure:
- Login into new VC6.2 as "vyatta"user
- changed to root "sudo su root"
- typed "configure"
- went to directory "cd /opt/vyatta/etc/config/"
- edited file with "vi config.boot"
- pasted whole old config.boot file from old VC6.1
- changed MAC addresses and passwords
- saved from vi editor ":wq"
- checked, if config.boot is proper size and permissions:
-rw-rw---- 1 root vyattacfg 39786 Mar 21 02:31 config.boot
- "exit" to end configure session
- reboot
But PROBLEM: New VC 6.2 does not want to boot with old config file. It always creates a new one, with just basic config in /opt/vyatta/etc/config/config.boot
Any idea what am I missing?
...and if it is the right way to do?

Partially solved:
After a dozen of coffee cups, I found this excellent script, which converts config.boot into vyatta commands: http://vyatta.remotemanage.net/
Of course, above script output needed some hour or so of editing, like new MAC, some sorting of rules to be more user-friendly, and I also combined many firewall rules to get a really nice config.
I applied them to new VC 6.2 and...
Oups!
Now I found this is a BUG in VC6.2, which does not handle multithreaded NIC adapters. And VMXNET3 adapter in VMWare ESX is exactly that - multithreaded.
BUG: https://bugzilla.vyatta.com/show_bug.cgi?id=6845
Unfortunatelly, I did not find any VC 6.2 LIVE-CD version newer than 9/2/2011, and BUG was resolved at 16/3/2011.
So right now, I am stuck here.
What about changing your Guest vNIC type from VMXNET3 to E1000? Or are you hitting some performance limit that requires you to use the VMXNET3 adapter?
Actually I just noticed that you are running VC 6.2. VC 6.3 was released a few months ago, so perhaps try with VC 6.3?
Well...I was born just next to the Window, so I miss WebGUI in VC6.3 :D That's why I try to stick with VC6.2
What I would do is try and do "install image [vc6.1] first.
restore original config file and add vc6.2 image next to it.
The conversion of the config file will be done by the extra install image at first time booting.
That is how I would try and get it working.
btw: vc6.3 and vc6.4 are really stable and imho much faster performing than the vc6.[12] series. Might be the right time to start learning the cli ... ;-)