When placing the thing that lets me eat someone's lp, I got this crash -
http://pastebin.com/XEsFswdP

Dude, be a bit more precise :P.
Can you tell me exactly what happened? Placing the block in the world or putting the sacrificing stone in it?

Whoops sorry, wrote that up real quick while restarting my client. When I placed the soul transfer block on the ground next to a ztones block, I immediately got that crash. I couldn't log back in to the server until Fako mcedit'ed out the floor near me.

I've not been able to reproduce that. I consider it as a rogue crash. Reopen an issue if it happens again.