i know. the true pain of quarries not liking to work with claims. but i remember, from a different server i used to play, there was a solution, and it should still work. when you claim the quarry, stand in the claim and do ( /trust [buildcraft] ) This should work, i haven't tried it yet but it's a trick that gives a sigh of relief for people who can't make ender quarries yet, and a finger of rage from griefers who can no longer jar your mining operations
for anyone thats intrested GriefPrevention (protect your land) — MyM-Wiki 0.0.1 documentation lists most if not all of the fake players that is used by mods currently so go give it a read
