Would you like to share a link to your history and have our team review? Since you seem to be working at http://usegalaxy.org, this is more direct than attempting to send in parameters and sample data through Biostars.
Generate a share link, paste that into an email to email@example.com, and include a link to this post so we can associate the two. Be certain to leave all inputs and job runs in the analysis as undeleted and that all were executed/exist in the shared history. It would also be good to note the problematic NVC dataset by number so that the correct data is reviewed.
Thanks! Jen, Galaxy team