[Bozos of Bones]

Happened to me once. I had some kind of bug that prevented the vial of holy water from appearing in the Fields of Slaughter, so I had to edit it in. Suddenly, my sorcerer had a bunch of spells. The number of spells goes away after level up, and I've found that once you use up the actual number of spells you are allowed, it's also gone. The same thing happens with Druid Shapeshift, and maybe Bard spells too. I can also imagine Monk special attacks to suffer from the same bug, as it is basically on the same principle.