Let's hope they do, but assume that they don't. If you believe that the only way to get your memory speed up to par is to get out a soldering iron, like that article would have you believe, you're a whole lot more likely to do that than if you know you'll get most of the improvement without doing so. This is extremely delicate work highly hazardous to the health of your motherboard. It's not something you present as the only option when there are others available. If it's the first, I know a website that needs to get its act together.
Somebody has some explaining to do.
First, we need to determine how many KT266Pro motherboards have this problem, and how many don't. To ensure that possibility number three isn't true, we also need to confirm beyond a shadow of a doubt that the BIOS upgrade does provide significant improvement. Where you got it from and when. Once you find them, see whether the resistor is on R126, R127, or both, and tell me what you have. In all likelihood, you don't want to get out the soldering iron.