Hi Reuben, yeah in order for Network to be able to work, it needs to organize the curves into 2 separate crossing sets, and those sets should form a grid shape similar to how longitude and latitude lines on a globe can make a grid on a flat map. If you have arrangements that can not be "unwrapped" in to a regular flat grid then it won't work.

There's some more discussion on the type of arrangement that Network needs in some of these previous threads:

http://moi3d.com/forum/index.php?webtag=MOI&msg=4384.4
http://moi3d.com/forum/index.php?webtag=MOI&msg=1778.6

- Michael