Aiden Jepson

Hey guys I just want to let you know this JUST happened to me, on a server, in an area where creepers and TNT Cannot explode (Grief Prevent), in broad daylight, on the top of a mountain. I was making an automatic cobblestone generator using a redstone clock (Infinite redstone loop) and a piston, the piston always works once, but when the loop comes back around it explodes before it can activate, no damage except for the piston. Vanilla Minecraft 1.4.7. THERE IS NO WAY THERE WAS A CREEPER OR TNT! It keeps happening and I can't make my generator now, please help, if required will post a video. EDIT: Now that I think about it, it happened while I was trying to push a block outside of my land claim... Hmmm.