So apparently if you make a shop for buying/selling 32 ender pearls at a time, the stack glitch will trigger. See attached screen shot. I'd imagine this can occur with eggs, heck, maybe even 128 iron ingots at a time. This makes running an Ender Pearl exchange difficult or impossible. I hope this can get fixed somehow. Thanks, Mike
I think he's referencing the sign they posted about Stacked items get you banned from the arena. I think they only specify a few things and some people don't know they can't use enderpearls.