This shouldn't be resolved, I am still having this problem and I have no idea how to fix it!
I don't know if the problem is fixed specifically on that server because the portal to creative plots where I was making the map bigger was broken and told me to use proxy, which I didn't know what that meant. I originally ad this problem in 1.6.1, even though the problem was similar to another issue found in 1.4.5.
It was a crash not a bug even though the type says bug.
I don't know how to fix this problem.