The problem you are all facing deals with how the new boot loader software configures the router on boot. This case may apply not only to routers with SN# 12xxxxxx but with other serial numbers also. If you take a router and upgrade it to the newer tp-link factory firmware you will begin to face this problem regardless of what the serial number is and when it is produced.
The new bootloader was created by TP-LINK factory in last months of 2011 because they found bugs which they fixed. You are all certainly having this WAN port problem on 12xxxxxxxx numbers only because they are newly produced and the new boot loader is installed on it by factory. This is the connection between serial numbers and DD-WRT WAN port problems.
Boot loader is a software produced by the factory that made the router. It controls the existence of an operating system and how that operating system boots. The operating system is the tp-link firmware at first, and if changed, it may become DD-WRT if the user wants so. But the boot loader stays one and same even if the firmware is changed.
The new TP-LINK boot loader contains fixes to important problems that were found after it was released at first. This includes problems that wired computers may not connect to internet if the router reboots and they must renew their ip address if that happens.
I cannot recommend anyone to downgrade their tp-link firmware as these instructions say. This is like downgrading your computer's bios version because an improvement to the newer bios improves windows 7 but does no longer allow windows xp to boot. Yes you get it working this way but you generate risks of new problems arising with the whole system of your router.
My special recommendation that would generally work for all of you is the following:
- If you already downgraded your boot loader with the german firmware, wait until a new DD-WRT beta arrives and after that please do: webrevert to factory, then upgrade to factory newest firmware so that you restore the new boot loader, then upgrade to dd-wrt with factory-to-ddwrt.bin
- If you have never downgraded your boot loader, then wait with the factory firmware until a new dd-wrt build arrives, then upgrade to factory newest and then upgrade to dd-wrt latest with factory-to-ddwrt.bin.
Any new DD-WRT that may appear after current ones are compatible with the newer TP-LINK firmware without problems. This case was thoroughly tested with developers and confirmed to be true.
I hope to have explained the situation so that it is now clear to everyone what you do to get it working and why it is not good.
So, any expectation when a new beta version will be released?
I mean something like "3 to 6 months", or "no more than X months" or even "expect nothing for at least 1 year".
Since I am a regular user I don't know what the intention of the developers is. I am just explaining why things you do are not recommended although they make a fix or patch that seems to work. But I have a feeling that new build will be before Christmas