I think it was a crash trying to open the GUI - have you tested this further and tried it again? Try dedicating more than 1gb of RAM by the way, there is the potential for OOM crashes that don't say they are OOM crashes...
Didn't get the chance to open the Gui, I placed it down, and it was an instant crash. gave it another go that night with the same result in a different world. I've already tried allocating two, but it makes my game run slower.
On SP does the world roll back or does the internal server manage to shut down properly and leave the machine in the world? If it leaves the recycler, can you use it? Have you tried on a server? What are your system specs and hardware? (Not important for the crash, but could explain why more ram == slower mc for you)
I should probably try and test some of these bugs myself!