NL - nlpack file problems

It seems like quite a few people are posting NL tracks with nlpack file extensions rather than nltrack extensions. I have been unable to load and ride those with nlpack extensions. Is there something I'm not doing right, or a patch or update I need?

[hyyyper]

there's this program that allows you to include 3ds and other files,

the site is http://www.gravimetricstudios.com and the search for the track packager

Thanks for the info and address Hyyyper. I will check it out right away.