Bukkit

What steps will reproduce the problem?
1. Set "EdgeMarker" to an item id
2. Claim an area

What is the expected output? What do you see instead?
Expected output, fence around the edges.
What I see instead, smoke (that makes some players lag)

What version of the product are you using?
v 1.0.2 with Bukkit R0.2 #2774 for MC 1.5.2.

Please provide any additional information below.
Config:
#If not set to -1, an item of the given id will be placed along the edges of newly bought chunks
EdgeMarkerID = 85