It's nothing to worry about. The full explanation of why is pretty technical, but I think I have some examples that might give a general idea why this happens:
Think about how we use English today, and how it was used 300-400 years ago. Many words are the same, and the general structure is similar, but there are differences. Let's say, for example, we took a person from back then, handed them a gun and taught them what it was and how to use it. Now, if we wanted this person to shoot something, we'd probably say something like "fire". Instead of shooting, this person would likely look around and ask you where the fire was. This is similar to what happens in a computer program when two versions interpret the same command or piece of data differently.
The other, more likely case is this:
Let's say you and your friends wanted to be cute and start talking like Yoda (where you reverse the subject and verb phrases). And let's pretend that it really caught on and soon that was the way everyone talked. At some point, people might even forget that a sentence could be structured any other way. If you took someone from today and someone from this imaginary scenario, they'd have a hard time communicating with each other. Thinks to the amazing capabilities of the human brain, they'd probably figure out fairly quickly how to understand each other, but it'd probably involve a lot of conscious thought.
While this isn't likely to happen in real life, it can happen rather easily in a computer program. For instance, you could write in your code that when you tell another computer about a brick, you will send the position, color, and owner in that order. However, the compiler might decide that it thinks it is more efficient to send the information ordered as owner, position, and color. The decision to reorder the information varies between different compilers, and even different versions of the same compiler. Some compilers even offer options that can influence this. Even using the same compiler with the same options can cause this if changes elsewhere in the code cause it to reorder certain things. Sure, there are ways to prevent this, but they aren't worth the effort, especially if you want all the users to use the same version of your software.
It's just easier for Badspot to not care about maintaining compatibility. It just happens to have the side effect of keeping people out of the beta server he doesn't want bugging him.
I hope this clears up any confusion and puts to rest any fears.
