I've just joined in the last few days and I've seen that the wilderness areas are a very heavily played out with holes, trenches and abandoned buildings all over the place. To make it easier to get around I started to build floating walkways by crouching, walking backwards, looking down and automatically placing blocks as I go.
I've been able to do this on my own LAN server and a few other online servers but for some reason when I do it here I place about 20-30 blocks then fall off and die. Is there a rule about not building such 1 x ?-block-long structures? I've looked at the rules and can't find anything that covers them.