At the University of Luxembourg, we are experiencing a bug where *.nam files which are generated with data out of order (i.e. nodes are listed in an order different than their ID order) will not display correctly.
To reproduce, extract the files I have attached and run the command given in 'run'. It should run the 'three-tier debug' profile with a load factor of 0.3, and generate a file called 'main.nam'. (you may have to recreate some directory structure to get it to work).
I have also included in the attached archive a sample of the first 1000 lines of the main.nam file generated on my machine, and a screenshot of the problem in action.
A solution script is also included in the archive, which re-orders the generated file so that nodes are configured in the order of their IDs.