The red arrow will show up when you land at co-ordinates that differ from the co-ordinates on the landmark. For example, on my sim, i have routed all tp's to the landing point. If someone TPs in using a LM that used to drop them in another part of my land, they will see the red arrow. If they have a LM that points directly to the landing point, then they won't see a red arrow. The arrows are very helpful when you land in a mall, for example, and the arrow points to the store you are looking for. Simply follow the arrow. :-) I used to find them annoying, too. But they're too helpful for me to want them gone permanently.