Need instructions to update FVS318Gv2 firmware beyond 4.3.3.6

Dane,

Never mind.  I figured out how to do the telnet/TFTP solution myself, and IT ACTUALLY WORKED!

So, in order to help other users solve the "GUI firmware updates disabled by v4.3.3-6" problem, here is my solution in all it's gory detail (Windows 7-only, sorry; maybe someone else can post the MacOS version):

Use at your own risk; this is only a tale of what worked for me.  Since my network configuration is likely different from yours, you'll have to reinterpret this information for your own setup.  Good luck.  I already had all other ports besides mine disconnected at the router from trying the TFTP solution that did not work; I do not know if this factor is important to my success. I did not have the WAN port disconnected.

First, if you haven't already done so, enable the Telnet Client on your PC:

1. Click Start > Control Panel > Programs and Features.
2. Click Turn Windows features on or off.
3. In the Windows Features dialog box, check the Telnet Client check box.
4. Click OK. The system enables the Telnet Client. This may take a minute or two.

Next, go to solarwinds.com free TFTP server

1. Click on Download Free Tool.
2. You'll have to register, but will then be guided to download the tool.  Or, you might just be able to get it here.
3. Unzip and install the tool, then fire it up.
4. Feel free to open the Help page from the tool menu and/or check out their Free Tools Forum here.

Now, copy the downloaded Netgear firmware image file (e.g. FVS318Gv2_v4.3.4-2.img) to the TFTP server root folder (C:\TFTP-Root is the default).

Open a Windows Command window (Type cmd in the Start>Search window and click the cmd icon).

[Note: in the text below, System prompts and responses are in CourierNew, your inputs are CourierNewBold, and my notes are Arial] 

C:\Users\<you>>telnet 192.168.1.1 (or whatever the IP address of your router is)

FVS318Gv2 login: admin (Your router admin username)

Password: (Type your router password—nothing will show up on the screen—then hit Enter)

************************************************
Welcome to FVS318Gv2 Command Line Interface
************************************************
FVS318Gv2> util firmware_upgrade FVS318Gv2_v4.3.4-2.img 192.168.1.<xx> (The IP address of your computer on the local network where the TFTP server is running)

FVS318Gv2_v4.3.4-2.i 100% |*******************************| 26324k --:--:-- ETA (this line progresses during the file upload)
chmod: /mnt/tmpfs/tr69Instance.map: No such file or directory
Start upgrade ...
/var/image/FVS318Gv2_v4.3.4-2.img length is 0x19b5000(26955776)
filename : ASL firmware
filelen : 0x19b4f00
filecrc : 0x445c81de
file version : 4.3.4-2
kernel offset : 0x100
kernel size : 0x7bfabb
fs offset : 0x8fff00
fs size : 0x10b5000
calculate crc is : 0x445c81de
crc check PASS
Writing File System to Flash ...
Done.
Writing Kernel to Flash ...
Done.
>Firmware Version Updated
mount: mounting /mnt/tmpfs/pfrm2.0 on /pfrm2.0 failed: No such file or directory
FVS318Gv2>

Connection to host lost. (This is when the router restarts after the update)

C:\Users\<you>>exit (This closes the cmd window)

Notice that you didn't have to restore your router to its factory default state before starting this procedure.  Nor did you lose any of your settings (password, firewall, etc.) in the process!!