Players can't use fire, despite having permision

So, people aren't able to use flint and steel for some reason on my server. I have not blacklisted flint & steel and fire spread is enabled in the Factions config and the Worldguard config. But nobody is able to ignite their portals unless I'm online to do it for them.

I'm running Windows 7 32 bit, Java 6 1.6.0_33 but my server is remotely hosted by Cloudcrafting. Their tech support is not very good at all.

My plugins are:

AntiCheat
AutosaveWorld
BOSEconomy
Buycraft
ChatManager
Chestshop
CombatTag
Essentials
EssentialsGeoIP
Factions
GroupManager
KitPlugin
mcMMO
Modifyworld
PermisiionsEx
PlayerLogger
RankMeUp
ShowcaseStandalone
SimpleJail
VanishNoPacket

I am not getting any errors in my log and it would seem I have the settings correct - people should be able to use fire (even default players), but they can't. Oh and the craftbukkit version I'm using is 1.3.1-R2.0

 

Modifyworld can be causing this problem! try disabling that plugin it could be it