Help with Mining Well code

direwolf20's mining well system crashes the server im playing on, the first time it runs, or if you make changes to it.
mainProg: http://pastebin.com/HpxVKWV1
Miner: http://pastebin.com/BA013Bhn
Video tutorial by direwolf20: http://www.youtube.com/watch?v=uXhBzaaEtAs
Can someone tell me how to fix it and whats wrong?

Split into new topic.