I'm running a tekkit 2.1.1 server for my son and I and I have come across a strange problem. I was putting some signs over my chests and when I got half way along when I couldn't set the sign message. As I was entering the message it gets deleted, I did a little bit of testing and in about half of my house i cannot set sign messages. Every couple of seconds whilst setting the message the message content would be deleted. I couldn't find any information about problems setting sign messages but this feels to intentional to be a bug.
Does anyone have any idea what is happening or where I can go to find more information about the problem?