I got past the first level no problem. Could have been a bad trim, bad download, bad extraction who knows. Re-download and trim it with NDS Tokyo Trim and then try it. If fails, back everything up and format.
yeah, download it from a different source. I had a problem in Jump Ultimate Stars, and I redownloaded it 2 times before realizing "durr, it's the same file!" and finding another site to download from.