No one on my server can place Smooth_Stone????

people on my server can place anything except smooth_stone (itemid = 1 ). I have looked through all my Plugins: BedHome, BorderGuard, HeroChat, iConomy, NoCheat, OKOre
XP, PermissionsEx, Questioner, VoxelSniper, WorldEdit, WorldGuard, ChatManager,
CommandBook, Modifyworld, Permissions, ChestShop, LWC, mcMMO, MobBounty, Monster
Hunt, Register, Towny

None of them seem to have a perm that blocks only smooth_stone. They have modifyworld.* so its not that. Admins with '*' perm can but I need everyone to be able to place stone. Please help if you can I don't know what to do. Also stone is not blacklisted in anything.

Thanks in advance for any help offered.

Joint.

Anyone? I really need to figure this out!

EDIT by Moderator: merged posts, please use the edit button instead of double posting.