I don't think thats the problem. I increased it several times but with no success. What bugs me is that it's seemingly random, it sometimes fails at a place where it didn't fail the last time. Anyways, my map:
http://i.imgur.com/z4HNiTN.png I marked the important points (where my character should be when it checks for it's position) to show off my amazing paint skills
This is the function that (should) find the current location btw: (based off of KeepBotting's iOak)
http://pastebin.com/uqvpiWvz
So there is quite some room for error. When it fails, it even places me somewhere near Edgeville when I'm actually standing at the Varrock lodestone for example. It's wierd :/