Based on your two posts, I went into the FATCAT demo to try the following (use SUMA to open up surfaces, then add tracts with DriveSuma):
$ cd ~/FATCAT_DEMO/DTI
$ suma -npb 10 -i ../Net_001.gii -niml &
$ DriveSuma -npb 10 -com viewer_cont -load_do o.NETS_AND_001.niml.tract
Assuming you have the FATCAT demo, does that work for you? Aand, even without that, is this the kind of thing you are entering on the command line, and in this order? I also notice that your first SUMA call in this post doesn't have a '-npb 10' listed, so I wasnt sure how that fit in.
--pt