Cash For Gold Achievment Impossible

Level 3 of HoG. You need to cast Blood Money 100 times. I've finished the level with 600 total spell casts. Then relaoded the save and had it go up to 800 *just* using Blood Money. It will not unlock.

Also in this level, the games FPS drops to 1 when putting gold into the Cauldron. Sometimes it goes back to normal after a few minutes, sometimes it doesnt. This only happened after I replayed the level but didn't happen on my first play.