Multi-threaded and multiple worlds

I am going to have a rather large and seperated game world, each part will have a Newton world. If I put each world in a different thread (not that I would, probably something like 3 in one and 3 in another as an example) are there any issues with globals or singletons in either OgreNewt or Newton that I need to be aware of? Is there any thread specific memory used, if not, could I run the update of the Netwon world's in different threads so that, for example, world0 may be updated inside thread2, the next update may take place in thread1, the next could take place in thread3. Doing it this way would be far better for my worker design pattern.

Newton is not thread safe it uses a global memory manager. Please my thread here and try to convince Julio to at least release point source releases and help dispel all the FUD that people spread on the forum about open source. The thread is here (the off topic rant at the bottom ).

Yes I remember Julio saying in his forum that currently Newton has only a single world (hence, the singleton design) but this will be changed in the next release of Newton. Maybe the better place is to post the question in the Newton forum itself.

The related thread http://newtondynamics.com/forum/viewtopic.php?t=2852

Been a while since I've been over there (I try to minimize my time on phpBB forums, too many issues I have with them). Will continue over there. I really would prefer to use Newton, don't want to head to PhysX (gull, I even hate the name...).