Hi, I'm the plugin developer of Safe Creeper and I was just asking what version you are really using (Craft Bukkit server), you could check it using the command '/ver'. Safe Creeper should work with all craft bukkit version above 1.2.5-R1.2. Or is there any other thing that didn't work, please tell me.
Oh, and for more support, post the problem on the page of Safe Creeper next time
Tim Visée