Potential way to fix the problem with cross compatibility.

The use of the #if statements could work

Courtesy of http://gafferongames.com/networking-for-game-programmers/sending-and-receiving-packets/

Yes, the website is for gaming, but the code could apply to our situation with cross compatibility.

Note, this isn't the finalized version that I would send, just have a look over at the potential code that we could use. If this is fine, then I'll try and integrate it in properly.