Pretty much what the subject says - when this https://gist.github.com/1334810 had hard tabs in it, a cut-and-paste to the Codify editor looked mad crazy, with lines all transposed and such - but the app worked (surprised the hell out of me!), so I know it’s a display issue.
When I replaced the hard tabs with 3 spaces, and tried the cut-and-paste again, perfection.