1. Place three extended drawbridges down in a super flat world.
2. Put three pieces of dirt in each of them, and one piece of dirt next to the row of drawbridges.
3. Run a length of redstone along the top with a lever on the extra piece of dirt.
4. Flip lever - functions properly.
5. Remove redstone and replace with bluestone wire.
6. Flip lever. Crash.

Build 754

Tweet/msg me if you want to join a quick world for a demo.

Drawbridges tend to crash quite often when trying to receive a redstone signal but I'll look into it anyways.
All multiparts are being rewritten (including gates and bluestone), which will improve both performance and reliability even more than it did last time so it might get fixed then ^^

If you have a crashlog for us?

Sure thing.

I actually found a forked version of Mechworks that didn't crash on this. I'll get a crash log up for y'all tonight.