Weird block breaker machine crash bug.. thingy..

[judders]

Title: Weird block breaker machine crash bug.. thingy..

Version: 3.0.3/3.0.4

OS: Windows vista 32bit

Java Version: latest version, not sure on specifics

Description of Problem:

I have my tunnel boring machine and everytime i send it a signal to move in one direction, it crashes my tekkit, but not the server.. It only appears to happen when the block breakers touch a block, otherwise it moves around fine.. i don't know what to be looking for so i put the most recent log into pastebin and such, thanks for the help people!

Error Messages:

Error Log:

http://pastebin.com/a2kF53gf

[judders]

C'mon guys i really need some help here, it would be much appreciated