Have you tried yEd?
http://www.yworks.com/en/products_yed_about.html
It is a java application and it can even run in a browser online, but it needs java 1.6, but this will be also solved in the near future.
http://www.yworks.com/en/products_yed_about.html
It is a java application and it can even run in a browser online, but it needs java 1.6, but this will be also solved in the near future.