As said Rootware, you have to rework the destroy part. Take a look here. http://www.maxcheaters.com/topic/179589-lifestonebogs-stackable/
For example
- player.destroyItem("Consume", spb, trainer, true);
+ if (Config.BOG_STACKABLE)
+ player.destroyItem("Consume", spbId, 1, trainer, true);
+ else
+ player.destroyItem("Consume", spb, trainer, true);
Originaly it was destroying the item, but when you made it stackable, you have to define to destroy only 1.