After having upgraded to the latest virtualbox the amd64 virtual machine keeps crashing, while the winxp and the i386 machines seem to work ok. I'm currently investigating to see if I can downgrade or do something else about it all. Unfortunately the amd64 machine also builds the API docs, so they won't be updated either until I fix the problem.
In the meantime, take a look on how to not have to keep downloading nightly builds: http://makehuman.blogspot.com/2010/08/u ... t-way.html