I just packed my own with wit and it seems to work fine. Tested it on Dolphin, was able to get to the map and complete 4-1.
Here's the list of files I've got, if you want to check it against your dirtree: http://dl.dropbox.com/u/4558613/FileList.txt
Yep, I'm 18 now I'm still around Jul and Kafuka (the two spinoffs of Acmlm's Board 2), though I'm rarely active on the forums, I usually just idle in IRC.
I was one of the two creators of Reggie, and that's what got me into this Newer mess... I'll probably make level editors for NSMB2/U when/if they're hackable, but I'm DEFINITELY not getting into another game project like this :|
Really you got it working? Awesome. That dropbox link doesn't work though, can you double check that you uploaded the file? Can you describe what you did to make it work?